• Conformal portal to dark matter

  Title	: Conformal portal to dark matter
  Journal	: PHYSICAL REVIEW D, 2021

  
  

  논문

  NUMBER	P21021
  AUTHOR	Ko, Pyungwon,Kaneta, Kunio
  TITLE	Conformal portal to dark matter
  ARCHIVE	2106.01923
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2021
  ABSTRACT	We propose a new portal coupling to dark matter by taking advantage of the nonminimally coupled portal sector to the Ricci scalar. Such a portal sector conformally induces couplings to the trace of the energy-momentum tensor of matters including highly secluded dark matter particles. The portal coupling is so feeble that dark matter is produced by freeze-in processes of scatterings and/or the decay of the mediator. We consider two concrete realizations of the portal: conformally induced Higgs portal and conformally induced mediator portal. The former case is compatible with the Higgs inflation, while the latter case can be tested by dark matter direct detection experiments.

  
  

  

• A multi-component SIMP model with U(1)(X) -> Z(2) x Z(3)

  Title	: A multi-component SIMP model with U(1)(X) -> Z(2) x Z(3)
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2021

  
  

  논문

  NUMBER	P21008
  AUTHOR	Ko, Pyungwon
  TITLE	A multi-component SIMP model with U(1)(X) -> Z(2) x Z(3)
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2021
  ABSTRACT	Multi-component dark matter scenarios are studied in the model with U(1)(X) dark gauge symmetry that is broken into its product subgroup Z(2) x Z(3) a la Krauss-Wilczek mechanism. In this setup, there exist two types of dark matter fields, X and Y, distinguished by different Z(2) x Z(3) charges. The real and imaginary parts of the Z(2)-charged field, X-R and X-I, get different masses from the U(1)(X) symmetry breaking. The field Y, which is another dark matter candidate due to the unbroken Z(3) symmetry, belongs to the Strongly Interacting Massive Particle (SIMP)-type dark matter. Both X-I and X-R may contribute to Ys 3 -> 2 annihilation processes, opening a new class of SIMP models with a local dark gauge symmetry. Depending on the mass difference between X-I and X-R, we have either two-component or three-component dark matter scenarios. In particular two- or three-component SIMP scenarios can be realised not only for small mass difference between X and Y, but also for large mass hierarchy between them, which is a new and unique feature of the present model. We consider both theoretical and experimental constraints, and present four case studies of the multi-component dark matter scenarios.

  
  

  

• Dark matter physics in dark SU(2) gauge symmetry with non-Abelian kinetic mixing

  Title	: Dark matter physics in dark SU(2) gauge symmetry with non-Abelian kinetic mixing
  Journal	: PHYSICAL REVIEW D, 2021

  
  

  논문

  NUMBER	P20036
  AUTHOR	Ko, P.,Nomura, Takaaki
  TITLE	Dark matter physics in dark SU(2) gauge symmetry with non-Abelian kinetic mixing
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2021
  ABSTRACT	We investigate a model of dark sector based on non-Abelian SU(2)(D) gauge symmetry. This dark gauge symmetry is broken into discrete Z(2) via vacuum expectation values of two real triplet scalars, and an SU(2)(D) doublet Dirac fermion becomes Z(2)-odd particles whose lighter component makes stable dark matter candidate. The standard model and dark sector can be connected via the scalar mixing and the gauge kinetic mixing generated by higher dimensional operators. We then discuss relic density of dark matter and implications to collider physics in the model. The most unique signatures of this model at the LHC would be the dark scalar (Phi(())(1)) productions where it subsequently decays into: (1) a fermionic dark matter (chi(l)) and a heavy dark fermion (chi(h)) pair, Phi(())(1) -> (chi) over bar (1) chi(h) ((chi) over bar (h)chi(l)), followed by chi(h) decays into chi(l) and non-Abelian dark gauge bosons (X-is) which decays into SM fermion pair (f) over bar (SM)f(SM) resulting in the reaction pp -> Phi(())(1) -> (chi) over bar (1) chi(h) ((chi) over bar (h)chi(l)) -> f(SM)(f) over bar (SM)f(SM) (2) a pair of X-i s followed by X-i decays into a DM pair or the SM fermions resulting in the reaction, pp -> Phi(())(1) -> XiXi -> (chi) over bar (l) chi(l) f(SM) (f) over bar (SM) or even number of f(SM) (f) over bar (SM) pairs.

  
  

  

• Exploring properties of long-lived particles in inelastic dark matter models at Belle II

  Title	: Exploring properties of long-lived particles in inelastic dark matter models at Belle II
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2021

  
  

  논문

  NUMBER	P21001
  AUTHOR	Ko, P.,Lu, Chih-Ting,Kang, Dong Woo
  TITLE	Exploring properties of long-lived particles in inelastic dark matter models at Belle II
  ARCHIVE	2101.02503
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2021
  ABSTRACT	The inelastic dark matter model is one kind of popular models for the light dark matter (DM) below O(1) GeV. If the mass splitting between DM excited and ground states is small enough, the co-annihilation becomes the dominant channel for thermal relic density and the DM excited state can be long-lived at the collider scale. We study scalar and fermion inelastic dark matter models for O(1) GeV DM at Belle II with U(1)(D) dark gauge symmetry broken into its Z(2) subgroup. We focus on dilepton displaced vertex signatures from decays of the DM excited state. With the help of precise displaced vertex detection ability at Belle II, we can explore the DM spin, mass and mass splitting between DM excited and ground states. Especially, we show scalar and fermion DM candidates can be discriminated and the mass and mass splitting of DM sector can be determined within the percentage of deviation for some benchmark points. Furthermore, the allowed parameter space to explain the excess of muon (g- 2)(mu) is also studied and it can be covered in our displaced vertex analysis during the early stage of Belle II experiment.

  
  

  

• Semi-annihilating Z(3) dark matter for XENON1T excess

  Title	: Semi-annihilating Z(3) dark matter for XENON1T excess
  Journal	: PHYSICS LETTERS B, 2021

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.
  TITLE	Semi-annihilating Z(3) dark matter for XENON1T excess
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, 2021
  ABSTRACT	The recently reported result from XENON1T experiment indicates that there is an excess with 3.5ssignificance in the electronic recoil events. Interpreted as new physics, new sources are needed to account for the electronic scattering. We show that a dark fermion psi with mass about O(10) MeV from semiannihilation of Z(3) dark matter X and subsequent decay of a dark gauge boson V-mu may be responsible for the excess. The relevant semi-annihilation process is X+ X -> (X) over bar+ V-mu(->psi+(psi) over bar), in which the final.has a box-shape energy spectrum. The fast-moving.can scatter with electron through an additional gauge boson that mixes with photon kinetically. The shape of the signals in this model can be consistent with the observed excess. The additional interaction with proton makes this model testable in future searches for nucleus recoil as well. Because of the lightness of invisible particle introduced, this scenario requires non-standard cosmology to accommodate the additional radiation component. (C) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3.

  
  

  

• Proceedings of the second MADANALYSIS 5 workshop on LHC recasting in Korea

  Title	: Proceedings of the second MADANALYSIS 5 workshop on LHC recasting in Korea
  Journal	: MODERN PHYSICS LETTERS A, 2021

  
  

  논문

  NUMBER
  AUTHOR	Ko, Pyungwon
  TITLE	Proceedings of the second MADANALYSIS 5 workshop on LHC recasting in Korea
  ARCHIVE
  FILE
  JOURNAL	MODERN PHYSICS LETTERS A, 2021
  ABSTRACT	We document the activities performed during the second MADANALYSIS 5 workshop on LHC recasting, that was organised in KIAS (Seoul, Korea) on February 12-20, 2020. We detail the implementation of 12 new ATLAS and CMS searches in the MADANALYSIS 5 Public Analysis Database, and the associated validation procedures. Those searches probe the production of extra gauge and scalar/pseudoscalar bosons, supersymmetry, seesaw models and deviations from the Standard Model in four-top production.

  
  

  

• XENON1T excess in local Z(2) DM models with light dark sector

  Title	: XENON1T excess in local Z(2) DM models with light dark sector
  Journal	: PHYSICS LETTERS B, 2020

  
  

  논문

  NUMBER	P20032
  AUTHOR	Ko, P.,Kim, Jongkuk
  TITLE	XENON1T excess in local Z(2) DM models with light dark sector
  ARCHIVE	Hep-ph/2006.16876
  FILE
  JOURNAL	PHYSICS LETTERS B, 2020
  ABSTRACT	Recently XENON1T Collaboration announced that they observed some excess in the electron recoil energy around a 2-3 keV. We show that this excess can be interpreted as exothermic scattering of excited dark matter on atomic electron through dark photon exchange. We consider DM models with local dark U(1) gauge symmetry that is spontaneously broken into its Z(2) subgroup by Krauss-Wilczek mechanism. In order to explain the XENON1T excess with the correct DM thermal relic density within freeze-out scenario, all the particles in the dark sector should be light enough, namely similar to O (100) MeV for scalar DM and similar to O (1 - 10) MeV for fermion DM cases. And even lighter dark Higgs phi plays an important role in the DM relic density calculation: XX dagger -> Zphi for scalar DM (X) and chi(chi) over bar -> phi phi for fermion DM (chi) assuming m(Z) -> m(chi). Both of them are in the p-wave annihilation, and one can easily evade stringent bounds from Planck data on CMB on the s-wave annihilations, assuming other dangerous s-wave annihilations are kinematically forbidden. (C) 2020 The Author(s). Published by Elsevier B.V.

  
  

  

• Dark matter bound state formation in fermionic Z(2) DM model with light dark photon and dark Higgs boson

  Title	: Dark matter bound state formation in fermionic Z(2) DM model with light dark photon and dark Higgs boson
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2020

  
  

  논문

  NUMBER
  AUTHOR	Ko, Pyungwon,Matsui, Toshinori,Tang, Yi-Lei
  TITLE	Dark matter bound state formation in fermionic Z(2) DM model with light dark photon and dark Higgs boson
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2020
  ABSTRACT	If fermionic dark matter (DM) is stabilized by dark U(1) gauge symmetry that is spontaneously broken into its subgroup Z(2), the particle contents of the model becomes very rich: DM and excited DM, both of them are Majorana fermions, as well as two dark force mediators, dark photon and dark Higgs boson are naturally present due to the underlying dark gauge symmetry. In this paper, we study the DM bound state formation processes within this scenario, assuming both dark photon and dark Higgs are light mediators and including the effects of excited DM. The Goldstone boson contributions to the potential matrix in the Schrodinger equations are found to be important. The emissions of a longitudinal vector boson (or somehow equivalently a Goldstone boson) during the DM bound state formations are crucial to induce a significant reannihilation process, reducing the dark matter relic abundance. Most of the stringent constraints for this kind of dark matter considered in the literature are simply evaded.

  
  

  

• Heavy dark matter through the dilaton portal

  Title	: Heavy dark matter through the dilaton portal
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2020

  
  

  논문

  NUMBER	P20055
  AUTHOR	Ko, Pyungwon,Kang, Dong Woo
  TITLE	Heavy dark matter through the dilaton portal
  ARCHIVE	2007.08546
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2020
  ABSTRACT	We re-examine current and future constraints on a heavy dilaton coupled to a simple dark sector consisting of a Majorana fermion or a Stuckelberg vector field. We include three different treatments of dilaton-Higgs mixing, paying particular attention to a gauge-invariant formulation of the model. Moreover, we also invite readers to re-examine effective field theories of vector dark matter, which we show are missing important terms. Along with the latest Higgs coupling data, heavy scalar search results, and dark matter density/direct detection constraints, we study the LHC bounds on the model and estimate the prospects of dark matter production at the future HL-LHC and 100 TeV FCC colliders. We additionally compute novel perturbative unitarity constraints involving vector dark matter, dilaton and gluon scattering.

  
  

  

• Reinterpretation of LHC results for new physics: status and recommendations after run 2

  Title	: Reinterpretation of LHC results for new physics: status and recommendations after run 2
  Journal	: SCIPOST PHYSICS, 2020

  
  

  논문

  NUMBER
  AUTHOR	Ko, Pyungwon
  TITLE	Reinterpretation of LHC results for new physics: status and recommendations after run 2
  ARCHIVE
  FILE
  JOURNAL	SCIPOST PHYSICS, 2020
  ABSTRACT	We report on the status of efforts to improve the reinterpretation of searches and measurements at the LHC in terms of models for new physics, in the context of the LHC Reinterpretation Forum. We detail current experimental offerings in direct searches for new particles, measurements, technical implementations and Open Data, and provide a set of recommendations for further improving the presentation of LHC results in order to better enable reinterpretation in the future. We also provide a brief description of existing software reinterpretation frameworks and recent global analyses of new physics that make use of the current data.

  
  

  

• Top FCNC induced by a Z boson

  Title	: Top FCNC induced by a Z boson
  Journal	: PHYSICAL REVIEW D, 2020

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.
  TITLE	Top FCNC induced by a Z boson
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2020
  ABSTRACT	We consider a Z model in which the Z boson couples only to up and top quarks. For a simple setup, one can consider a family-dependent U(1) symmetry, under which only right-handed up-type quarks are charged. After symmetry breaking, the right-handed quarks mix with each other, and top flavor-changing neutral currents (FCNCs) mediated by the Z boson can be generated at tree level. We take into account several processes at the parton level to probe the top FCNCs and find that the same-sign top quark pair production or the triple top quark production is the most capable of testing the top FCNCs. We also consider a few non-FCNC processes to probe the Z boson, for example, dijet production at the LHC. Finally, we perform numerical analysis at detector level and find that the same-sign top quark pair production provides a much more stringent bound on the FCNC coupling than the other processes in most of the parameter space.

  
  

  

• Correlation between RD() and top quark FCNC decays in leptoquark models

  Title	: Correlation between RD() and top quark FCNC decays in leptoquark models
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2019

  
  

  논문

  NUMBER	P19034
  AUTHOR	Ko, Pyungwon,Park, Jiwon,Li, Jinmian
  TITLE	Correlation between RD() and top quark FCNC decays in leptoquark models
  ARCHIVE	arXiv:1812.08484 title='고병원의 Archive' target=_blank > hep-ph > arXiv:1812.08484
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2019
  ABSTRACT	Some interpretations of RD anomaly in B meson decay using leptoquark (LQ) models can also generate top quark decays through Flavor Changing Neutral Current (FCNC). In this work we focus on two LQs, i.e. scalar S-1 and vector U-1 which are both singlet under the SU(2)(L) gauge group in the Standard Model (SM). We investigate their implications on the 3-body top FCNC decays t -> cl(i)l(j) at tree level and the 2-body t -> cV at one-loop level, with l being the SM leptons and V = gamma, Z, g being the SM gauge bosons. We utilize the 2 sigma parameter fitting ranges of the LQ models and find that Br(t -> cl(i)l(j)) at tree level can reach O(10(-6)) and Br(t -> cV) at one-loop level can reach O(10(-10)). Some quick collider search prospects are also analyzed.

  
  

  

• b -> s mu(+)mu(-) anomalies and related phenomenology in U(1)(B3-x mu)L-mu-x(tau)L(tau) flavor gauge models

  Title	: b -> s mu(+)mu(-) anomalies and related phenomenology in U(1)(B3-x mu)L-mu-x(tau)L(tau) flavor gauge models
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2019

  
  

  논문

  NUMBER	P19009
  AUTHOR	Ko, P.,Nomura, Takaaki
  TITLE	b -> s mu(+)mu(-) anomalies and related phenomenology in U(1)(B3-x mu)L-mu-x(tau)L(tau) flavor gauge models
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2019
  ABSTRACT	We propose a generation dependent lepton/baryon gauge symmetry, UX (with x + x = 1 for anomaly cancellation), as a possible solution for the b s(+-) anomalies. By introducing two Higgs doublet fields, we can reproduce the observed CKM matrix, and generate flavor changing Z interactions in the quark sector. Thus one can explain observed anomalies in b s(+-) decay with the lepton non-universal U(1)(X) charge assignments. We show the minimal setup explaining bs(+-) anomalies, neutrino masses and mixings and dark matter candidate, taking into account experimental constraints of flavor physics such as charged lepton flavor violations and the Bs-B

  
  

  

• Light dark matter showering under broken dark U(1) revisited

  Title	: Light dark matter showering under broken dark U(1) revisited
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2019

  
  

  논문

  NUMBER	P18105
  AUTHOR	Ko, Pyungwon,Yokoya, Hiroshi,Chen, Junmou
  TITLE	Light dark matter showering under broken dark U(1) revisited
  ARCHIVE	hep-ph/1807.00530
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2019
  ABSTRACT	It was proposed recently that different chiralities of the dark matter (DM) fermion under a broken dark U(1) gauge group can lead to distinguishable signatures at the LHC through shower patterns, which may reveal the mass origin of the dark sector. We study this subject further by examining the dark shower of two simplified models, the dubbed Chiral Model and the Vector Model. We derive a more complete set of collinear splitting functions with power corrections, specifying the helicities of the initial DM fermion and including the contribution from an extra degree of freedom, the dark Higgs boson. The dark shower is then implemented with these splitting functions, and the new features resulting from its correct modelling are emphasized. It is shown that the DM fermion chirality can be differentiated by measuring dark shower patterns, especially the DM jet energy profile, which is almost independent of the DM energy.

  
  

  

• Impact of the 125 GeV Higgs boson on singlet fermion dark matter searches at the LHC

  Title	: Impact of the 125 GeV Higgs boson on singlet fermion dark matter searches at the LHC
  Journal	: PHYSICAL REVIEW D, 2018

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.,Li, Jinmian
  TITLE	Impact of the 125 GeV Higgs boson on singlet fermion dark matter searches at the LHC
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2018
  ABSTRACT	The search for singlet fermion dark matter at high-energy colliders is commonly analyzed with a singlet scalar mediator, which however violates the standard model (SM) gauge invariance, renormalizability and unitarity. These problems can be cured by introducing a mixing between the singlet scalar s and the SM Higgs boson h. Thus one has to consider two scalar mediators h(1) and h(2), where h(1) is identified as the discovered 125 GeV Higgs boson. As a specific example, we consider the dark matter (DM) search in the t (t) over bar + is not an element of(T) channel. According to the masses of dark matter and two scalar mediators, we classify the process into four cases. By investigating the total cross sections and differential distributions, we find that the contribution of the 125 GeV Higgs boson h(1) cannot be neglected in all cases and can even dominate once h(1) is on shell in dark matter production. Further, we study the impact of h(1) on the LHC bounds of dark matter searches in the hadronic and semileptonic channels with the integrated luminosity of 36 fb(-1). Finally we make a brief comment that h(1) should be also considered in the vector DM search at high-energy colliders.

  
  

  

• Particle, Astroparticle Physics and Cosmology in Dark Matter Models with Dark Gauge Symmetries

  Title	: Particle, Astroparticle Physics and Cosmology in Dark Matter Models with Dark Gauge Symmetries
  Journal	: JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2018

  
  

  논문

  NUMBER
  AUTHOR	Ko, Pyungwon
  TITLE	Particle, Astroparticle Physics and Cosmology in Dark Matter Models with Dark Gauge Symmetries
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2018
  ABSTRACT	In this review, I describe a class of dark matter (DM) models where DM is either stable due to unbroken dark gauge symmetries, or long-lived due to accidental global symmetries resulting from the underlying dark gauge symmetries. Within these models, I discuss various topics on DM in the context of particle and astroparticle physics and cosmology: DM thermal relic density and (in)direct detection, Higgs inflation assisted with Higgs portal interaction, dark radiation (DR), DM-DR interaction and suppression of the matter power spectrum at large k, strong first order phase transition and gravitational wave production, etc.. Especially I emphasize the importance of dark gauge symmetries, unitarity and renormalizability, and the limitation of the DM effective field theory (EFT) or simplified models for DM searches at high energy colliders, including the role of dark Higgs boson and dark gauge bosons.

  
  

  

• Resolving phenomenological problems with strongly-interacting-massive-particle models with dark vector resonances

  Title	: Resolving phenomenological problems with strongly-interacting-massive-particle models with dark vector resonances
  Journal	: PHYSICAL REVIEW D, 2018

  
  

  논문

  NUMBER
  AUTHOR	Ko, Pyungwon,Natale, Alexander
  TITLE	Resolving phenomenological problems with strongly-interacting-massive-particle models with dark vector resonances
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2018
  ABSTRACT	We consider a light dark matter candidate that is produced by the freeze-out mechanism with 3 -> 2 annihilations, the so-called strongly interacting massive particles (SIMPs). SIMPs are identified as dark pions in dark chiral perturbation theory (ChPT) in which both light mass and strong coupling needed for SIMPs can be realized by strong dynamics. In QCD-like theories with SU(3)(L) x SU(3)(R)/SU(3)(V) flavor symmetry, including dark vector mesons in the hidden local symmetry scheme, we illustrate that dark vector mesons unitarize the dark ChPT efficiently, thus determining the correct relic density condition within the validity of the dark ChPT.

  
  

  

• Prospects for discovery and spin discrimination of dark matter in Higgs portal DM models and their extensions at 100 TeV pp collider

  Title	: Prospects for discovery and spin discrimination of dark matter in Higgs portal DM models and their extensions at 100 TeV pp collider
  Journal	: EUROPEAN PHYSICAL JOURNAL C, 2018

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.,Li, Jinmian
  TITLE	Prospects for discovery and spin discrimination of dark matter in Higgs portal DM models and their extensions at 100 TeV pp collider
  ARCHIVE
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL C, 2018
  ABSTRACT	We study the discovery and discriminating prospects of the Higgs portal dark matter (DM) models for scalar, fermion and vector DM and their extensions in proton-proton (pp) collisions. The t (t) over bar +DM associated production in dileptonic final states is considered, in which the stransverse mass of two leptons is found to be effective in suppressing the Standard Model backgrounds along with the missing transverse energy and the angle between two leptons. The distributions of missing transverse energy and polar angle between two leptons are used for a discrimination of the spin nature of DM. For the proposed benchmark points, the discovery/exclusion can be made with an integrated luminosity less than 1 ab(-1) given a 1% systematic uncertainty, while the spin discrimination require integrated luminosity of a few O(10) ab(-1) given a 0.5% systematic uncertainty. The DM phenomenology is also discussed. A consistent DM candidate can be obtained either by extending our model where the Higgs portal couples to excited dark states that decay into DM, or modifying the coupling form into pseudoscalar.

  
  

  

• Heavy quark-philic scalar dark matter with a vector-like fermion portal

  Title	: Heavy quark-philic scalar dark matter with a vector-like fermion portal
  Journal	: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2018

  
  

  논문

  NUMBER
  AUTHOR	Ko, Pyungwon,Baek, Seungwon,Wu, Peiwen
  TITLE	Heavy quark-philic scalar dark matter with a vector-like fermion portal
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2018
  ABSTRACT	The absence of confirmed signal in dark matter (DM) direct detection (DD) may suggest weak interaction strengths between DM and the abundant constituents inside nucleon, i.e. gluons and valence light quarks. In this work we consider a real scalar dark matter S interacting only with SU(2)(L) singlet Up-type quarks U-i, = uR, c(R), t(R) via a vector like fermion 0 which has the same quantum number as U-i. The DM-nucleon scattering can proceed through both h-mediated Higgs portal (HP) and psi-mediated vector-like portal (VLP), in which HP can receive sizable radiative corrections through the new fermions. We first study the separate constraints on the new Yukawa couplings y(i) and find that the constraints of XENON1T results are strong on y(1) from VLP scattering and on y(3) from its radiative contributions to HP scattering. Since both DM-light quark interactions and HP have been well studied in the existing literature, we move forward to focus on DM heavy quark interactions. Since there is no valence c, t quark inside nucleons at mu(had) similar to 1 GeV, y(2), y(3) interactions are manifested in DM-gluon scattering at loop level. We find that renormalization group equation (RGE) and heavy quark threshold effects are important if one calculates the DM-nucleon scattering rate apsi at Mad 1 GeV while constructing the effective theory at mu(LEFT) similar to m(Z). For the benchmarks y(3) = 0.5, y(2) = 0.5,1, 3, combined results from Omega(DM)h(2) similar or equal to 0.12, XENON1T, Fermi-LAT, 13 TeV LHC data have almost excluded m(s) < m(t)/2 when only DM-{c, t} interactions are considered. FCNC of top quark can be generated at both tree level t -> psi(*),S -> cSS and loop level t -> c + gamma/g/Z, of which the branching fractions are typically below 10(-9) after passing the other constraints, which are still safe from the current top quark width measurements.

  
  

  

• Gravitational waves from first order electroweak phase transition in models with the U(1)(X) gauge symmetry

  Title	: Gravitational waves from first order electroweak phase transition in models with the U(1)(X) gauge symmetry
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2018

  
  

  논문

  NUMBER	P18013
  AUTHOR	Ko, Pyungwon,Matsui, Toshinori
  TITLE	Gravitational waves from first order electroweak phase transition in models with the U(1)(X) gauge symmetry
  ARCHIVE	arXiv:1802.02947
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2018
  ABSTRACT	We consider a standard model extension equipped with a dark sector where the U(1)(X) Abelian gauge symmetry is spontaneously broken by the dark Higgs mechanism. In this framework, we investigate patterns of the electroweak phase transition as well as those of the dark phase transition, and examine detectability of gravitational waves (GWs) generated by such strongly first order phase transition. It is pointed out that the collider bounds on the properties of the discovered Higgs boson exclude a part of parameter space that could otherwise generate detectable GWs. After imposing various constraints on this model, it is shown that GWs produced by multi-step phase transitions are detectable at future space-based interferometers, such as LISA and DECIGO, if the dark photon is heavier than 25 GeV. Furthermore, we discuss the complementarity of dark photon searches or dark matter searches with the GW observations in these models with the dark gauge symmetry.

  
  

  

• Strong first order EWPT & strong gravitational waves in Z(3)-symmetric singlet scalar extension

  Title	: Strong first order EWPT & strong gravitational waves in Z(3)-symmetric singlet scalar extension
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2018

  
  

  논문

  NUMBER	P17047
  AUTHOR	Ko, P.,Matsui, Toshinori,Kang, Zhaofeng
  TITLE	Strong first order EWPT & strong gravitational waves in Z(3)-symmetric singlet scalar extension
  ARCHIVE	arXiv:1706.09721
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2018
  ABSTRACT	The nature of electroweak (EW) phase transition (PT) is of great importance. It may give a clue to the origin of baryon asymmetry if EWPT is strong first order. Although it is a cross over within the standard model (SM), a great many extensions of the SM are capable of altering the nature. Thus, gravitational wave (GW), which is supposed to be relics of strong first order PT, is a good complementary probe to new physics beyond SM (BSM). We in this paper elaborate the patterns of strong first order EWPT in the next to simplest extension to the SM Higgs sector, by introducing a Z(3)-symmetric singlet scalar. We find that, in the Z(3)-symmetric limit, the tree level barrier could lead to strong first order EWPT either via three or two-step PT. Moreover, they could produce two sources of GW, despite of the undetectability from the first-step strong first order PT for the near future GW experiments. But the other source with significant supercooling which then gives rise to alpha similar to O(0.1) almost can be wholly covered by future space-based GW interferometers such as eLISA, DECIGO and BBO.

  
  

  

• Hidden charged dark matter and chiral dark radiation

  Title	: Hidden charged dark matter and chiral dark radiation
  Journal	: PHYSICS LETTERS B, 2017

  
  

  논문

  NUMBER	P17043
  AUTHOR	Ko, P.
  TITLE	Hidden charged dark matter and chiral dark radiation
  ARCHIVE	arXiv:1706.05605
  FILE
  JOURNAL	PHYSICS LETTERS B, 2017
  ABSTRACT	In the light of recent possible tensions in the Hubble constant H-0 and the structure growth rate sigma(8) between the Planck and other measurements, we investigate a hidden-charged dark matter (DM) model where DM interacts with hidden chiral fermions, which are charged under the hidden SU(N) and U(1) gauge interactions. The symmetries in this model assure these fermions to be massless. The DM in this model, which is a Dirac fermion and singlet under the hidden SU(N), is also assumed to be charged under the U(1) gauge symmetry, through which it can interact with the chiral fermions. Below the confinement scale of SU(N), the hidden quark condensate spontaneously breaks the U(1) gauge symmetry such that there remains a discrete symmetry, which accounts for the stability of DM. This condensate also breaks a flavor symmetry in this model and Nambu-Goldstone bosons associated with this flavor symmetry appear below the confinement scale. The hidden U(1) gauge boson and hidden quarks/Nambu-Goldstone bosons are components of dark radiation (DR) above/below the confinement scale. These light fields increase the effective number of neutrinos by delta N-eff similar or equal to 0.59 above the confinement scale for N = 2, resolving the tension in the measurements of the Hubble constant by Planck and Hubble Space Telescope if the confinement scale is less than or similar to 1 eV. DM and DR continuously scatter with each other via the hidden U(1) gauge interaction, which suppresses the matter power spectrum and results in a smaller structure growth rate. The DM sector couples to the Standard Model sector through the exchange of a real singlet scalar mixing with the Higgs boson, which makes it possible to probe our model in DM direct detection experiments. Variants of this model are also discussed, which may offer alternative ways to investigate this scenario. (C) 2017 The Author(s). Published by Elsevier B.V.

  
  

  

• Characterizing Higgs portal dark matter models at the ILC

  Title	: Characterizing Higgs portal dark matter models at the ILC
  Journal	: EUROPEAN PHYSICAL JOURNAL C, 2017

  
  

  논문

  NUMBER	P17033
  AUTHOR	Ko, P.,Li, Jinmian
  TITLE	Characterizing Higgs portal dark matter models at the ILC
  ARCHIVE	arXiv:1705.02149
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL C, 2017
  ABSTRACT	We study the dark matter (DM) discovery prospect and its spin discrimination in the theoretical framework of gauge invariant and renormalizable Higgs portal DM models at the ILC with root s = 500 GeV. In such models, the DM pair is produced in association with a Z boson. In the case of the singlet scalar DM, the mediator is just the SM Higgs boson, whereas for the fermion or vector DM there is an additional singlet scalar mediator that mixes with the SM Higgs boson, which produces significant observable differences. After careful investigation of the signal and backgrounds both at parton level and at detector level, we find the signal with hadronically decaying Z boson provides a better search sensitivity than the signal with leptonically decaying Z boson. Taking the fermion DM model as a benchmark scenario, when the DM-mediator coupling g(chi) is relatively small, the DM signals are discoverable only for benchmark points with relatively light scalar mediator H-2. The spin discriminating from scalar DM is always promising, while it is difficult to discriminate from vector DM. As for g(chi) approaching the perturbative limit, benchmark points with the mediator H-2 in the full mass region of interest are discoverable. The spin discriminating aspects from both the scalar and the fermion DM are quite promising.

  
  

  

• A flavor dependent gauge symmetry, predictive radiative seesaw and LHCb anomalies

  Title	: A flavor dependent gauge symmetry, predictive radiative seesaw and LHCb anomalies
  Journal	: PHYSICS LETTERS B, 2017

  
  

  논문

  NUMBER	P17007
  AUTHOR	Ko, P.,Nomura, Takaaki
  TITLE	A flavor dependent gauge symmetry, predictive radiative seesaw and LHCb anomalies
  ARCHIVE	arXiv:1701.05788
  FILE
  JOURNAL	PHYSICS LETTERS B, 2017
  ABSTRACT	We propose a predictive radiative seesaw model at one-loop level with a flavor dependent gauge symmetry U(1)(xB3-xe-mu+iota) tand Majorana fermion dark matter. For the neutrino mass matrix, we obtain an A(1) type texture ( with two zeros) that provides us several predictions such as the normal ordering for the neutrino masses. We analyze the constraints from lepton flavor violations, relic density of dark matter, and collider physics for the new U(1)(xB3-) (xe-mu+iota) tgauge boson. Within the allowed region, the LHCb anomalies in B -> K* mu (+) mu and B -> Kl (+) l with l = e or mu can be resolved, and such Z could be also observed at the LHC. (C) 2017 The Authors. Published by Elsevier B.V.

  
  

  

• LHCb anomaly and B physics in flavored Z models with flavored Higgs doublets

  Title	: LHCb anomaly and B physics in flavored Z models with flavored Higgs doublets
  Journal	: PHYSICAL REVIEW D, 2017

  
  

  논문

  NUMBER	P17015
  AUTHOR	Ko, P.
  TITLE	LHCb anomaly and B physics in flavored Z models with flavored Higgs doublets
  ARCHIVE	arXiv:1702.08666
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2017
  ABSTRACT	We study an extended Standard Model with a gauged U(1) flavor symmetry, motivated not only by the fermion mass hierarchy but also by the excesses in B -> K-(*())ll reported by the LHCb collaborations. The U(1) charges are assigned to quarks and leptons in a flavor-dependent manner, and flavored Higgs doublets are also introduced in order to detail the Yukawa couplings at the renormalizable level. Then, the fermion mass hierarchy is realized by the vacuum alignment of the Higgs doublets. In this model, flavor-changing currents involving the gauge boson of U(1) and the scalars generated by the Higgs doublets are predicted and the observables in the B -> K-(*())ll process possibly deviate from the Standard Model predictions. We study the possibility that these new flavor-changing interactions can explain the excesses in the B -> K-(*())ll process, and we derive some predictions for the other flavor-violating processes based on the analysis. We specifically investigate the Delta F = 2 processes and the other B decays: e.g., B -> X-s gamma and B -> D-(*())tau nu, where the deviations are reported by the Belle and BABAR collaborations.

  
  

  

• Probing a new strongly interacting sector via composite diboson resonances

  Title	: Probing a new strongly interacting sector via composite diboson resonances
  Journal	: PHYSICAL REVIEW D, 2017

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.
  TITLE	Probing a new strongly interacting sector via composite diboson resonances
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2017
  ABSTRACT	Diphoton resonance was a crucial discovery mode for the 125 GeV Standard Model Higgs boson at the Large Hadron Collider (LHC). This mode or the more general diboson modes may also play an important role in probing for new physics beyond the Standard Model. In this paper, we consider the possibility that a diphoton resonance is due to a composite scalar or pseudoscalar boson, whose constituents are either new hyperquarks Q or scalar hyperquarks (Q) over tilde confined by a new hypercolor force at a confinement scale Lambda(h). Assuming the mass m(Q) (or m((Q) over tilde))>> Lambda(h), a diphoton resonance could be interpreted as either a Q (Q) over bar (S-1(0)) state eta(Q) with J(PC) = 0(-+) or a (Q) over tilde(Q) over tilde (+) (S-1(0)) state eta((Q) over tilde) with J(PC) = 0(++) For the Q (Q) over bar scenario, there will be a spintriplet partner psi(Q) which is slightly heavier than eta(Q) due to the hyperfine interactions mediated by hypercolor gluon exchange; while for the (Q) over bar(Q) over bar (+) scenario, the spin-triplet partner chi(Q) over tilde arises from higher radial excitation with nonzero orbital angular momentum. We consider productions and decays of eta(Q),eta(Q) over tilde,psi(Q),and psi((Q) over tilde) at the LHC using the nonrelativistic QCD factorization approach. We discuss how to test these scenarios by using the Drell-Yan process and the forward dijet azimuthal angular distributions to determine the JPC quantum number of the diphoton resonance. Constraints on the parameter space can be obtained by interpreting some of the small diphoton excesses reported by the LHC as the composite scalar or pseudoscalar of the model. Another important test of the model is the presence of a nearby hypercolor-singlet but color-octet state like the S-1(0) state eta(8)(Q) or eta(8)((Q) over tilde), which can also be constrained by dijet or monojet plus monophoton data. Both possibilities of a large or small width of the resonance can be accommodated, depending on whether the hyper-glueball states are kinematically allowed in the final state or not.

  
  

  

• Explaining B -> K-(*())l(+)l(-) anomaly by radiatively induced coupling in U(1)(mu-tau) gauge symmetry

  Title	: Explaining B -> K-(*())l(+)l(-) anomaly by radiatively induced coupling in U(1)(mu-tau) gauge symmetry
  Journal	: PHYSICAL REVIEW D, 2017

  
  

  논문

  NUMBER	P17010
  AUTHOR	Ko, P.,Nomura, Takaaki
  TITLE	Explaining B -> K-(*())l(+)l(-) anomaly by radiatively induced coupling in U(1)(mu-tau) gauge symmetry
  ARCHIVE	arXiv:1702.02699
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2017
  ABSTRACT	We propose a scenario to generate flavor violating Z interactions at one-loop level by introducing U(1)(mu-tau) gauge symmetry, extra vectorlike quark doublets Q(a), and a singlet scalar chi. Both Q(a) and chi are charged under U(1)(mu-tau) and carry odd dark Z(2) parity. Assuming that chi is the dark matter (DM) of the Universe and imposing various constraints from a dark matter search, flavor physics, and a collider search for Q(a), one can show that radiative corrections to b -> sZ*-> sl(+)l(-) involving Q(a) and chi can induce Delta C-9 similar to -1, which can resolve the LHCb anomalies related with B -> K(*)l(+)l(-). Therefore, both DM and B physics anomalies can be accommodated in the model.

  
  

  

• Residual non-Abelian dark matter and dark radiation

  Title	: Residual non-Abelian dark matter and dark radiation
  Journal	: PHYSICS LETTERS B, 2017

  
  

  논문

  NUMBER	P16074
  AUTHOR	Ko, P.,Tang, Yong
  TITLE	Residual non-Abelian dark matter and dark radiation
  ARCHIVE	arXiv:1609.02307
  FILE
  JOURNAL	PHYSICS LETTERS B, 2017
  ABSTRACT	We propose a novel particle physics model in which vector dark matter (VDM) and dark radiation (DR) originate from the same non-Abelian dark sector. We show an illustrating example where dark SU(3) is spontaneously broken into SU(2) subgroup by the nonzero vacuum expectation value (VEV) of a complex scalar in fundamental representation of SU(3). The massless gauge bosons associated with the residual unbroken SU(2) constitute DR and help to relieve the tension in Hubble constant measurements between Planck and Hubble Space Telescope. In the meantime, massive dark gauge bosons associated with the broken generators are VDM candidates. Intrinsically, this non-Abelian VDM can interact with non-Abelian DR in the cosmic background, which results in a suppressed matter power spectrum and leads to a smaller sigma(8) for structure formation. (C) 2017 The Author(s). Published by Elsevier B.V.

  
  

  

• Minimal renormalizable simplified dark matter model with a pseudoscalar mediator

  Title	: Minimal renormalizable simplified dark matter model with a pseudoscalar mediator
  Journal	: PHYSICAL REVIEW D, 2017

  
  

  논문

  NUMBER	P17004
  AUTHOR	Ko, P.,Baek, Seungwon,Li, Jinmian
  TITLE	Minimal renormalizable simplified dark matter model with a pseudoscalar mediator
  ARCHIVE	1701.04131
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2017
  ABSTRACT	We consider a minimal renormalizable and gauge invariant dark matter (DM) model, in which the singlet fermion DM has only axial couplings to a new pseudoscalar mediator. The mixing between the pseudoscalar mediator and the standard model (SM) Higgs boson induces the interactions between the DM and SM particles. The DM candidate in this model can provide the correct thermal relic density and evades all direct detections, while it can produce observable signals in indirect detection experiments due to its large annihilation cross section. A comparative study for DM phenomenology at the LHC is conducted for models with scalar mediators that have either scalar or pseudoscalar couplings to SM particles and the DM. We find that the three scenarios have distinguishable features in scalar decay branching ratio, DM pair production cross section as well as the signal reaches at the LHC. The LHC searches for some visible signals related to the scalar sector are also discussed.

  
  

  

• Gravitational waves and Higgs boson couplings for exploring first order phase transition in the model with a singlet scalar field

  Title	: Gravitational waves and Higgs boson couplings for exploring first order phase transition in the model with a singlet scalar field
  Journal	: PHYSICS LETTERS B, 2017

  
  

  논문

  NUMBER	P16065
  AUTHOR	Ko, Pyungwon,Matsui, Toshinori
  TITLE	Gravitational waves and Higgs boson couplings for exploring first order phase transition in the model with a singlet scalar field
  ARCHIVE	arXiv:1609.00297
  FILE
  JOURNAL	PHYSICS LETTERS B, 2017
  ABSTRACT	We calculate the spectrum of gravitational waves originated from strongly first order electroweak phase transition in the extended Higgs model with a real singlet scalar field. In order to calculate the bubble nucleation rate, we perform a two-field analysis and evaluate bounce solutions connecting the true and the false vacua using the one-loop effective potential at finite temperatures. Imposing the Sakharov condition of the departure from thermal equilibrium for baryogenesis, we survey allowed regions of parameters of the model. We then investigate the gravitational waves produced at electroweak bubble collisions in the early Universe, such as the sound wave, the bubble wall collision and the plasma turbulence. We find that the strength at the peak frequency can be large enough to be detected at future space-based gravitational interferometers such as eLISA, DECIGO and BBO. Predicted deviations in the various Higgs boson couplings are also evaluated at the zero temperature, and are shown to be large enough too. Therefore, in this model strongly first order electroweak phase transition can be tested by the combination of the precision study of various Higgs boson couplings at the LHC, the measurement of the triple Higgs boson coupling at future lepton colliders and the shape of the spectrum of gravitational wave detectable at future gravitational interferometers. (C) 2017 The Authors. Published by Elsevier B.V

  
  

  

• Revisiting T2KK and T2KO physics potential and nu mu-(nu)over-bar mu beam ratio

  Title	: Revisiting T2KK and T2KO physics potential and nu mu-(nu)over-bar mu beam ratio
  Journal	: EUROPEAN PHYSICAL JOURNAL C, 2017

  
  

  논문

  NUMBER	P16036
  AUTHOR	Ko, Pyungwon
  TITLE	Revisiting T2KK and T2KO physics potential and nu mu-(nu)over-bar mu beam ratio
  ARCHIVE	arXiv:1605.02368
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL C, 2017
  ABSTRACT	We revisit the sensitivity study of the Tokaito- Kamioka-and-Korea (T2KK) and Tokai-to-Kamioka-andOki (T2KO) proposals where a water Cerenkov detector with the 100 kton fiducial volume is placed in Korea (L = 1000 km) and Oki island (L = 653 km) in Japan, respectively, in addition to the Super-Kamiokande for determination of the neutrino mass hierarchy and leptonic CP phase (delta(CP)). We systematically study the running ratio of the nu(mu) and (nu) over bar (mu) focusing beams with dedicated background estimation for the nu(e) appearance and nu(mu) disappearance signals, especially improving treatment of the neutral-current pi(0) backgrounds. Using a nu(mu)-(nu) over bar (mu) beam ratio between 3: 2 and 2.5: 2.5 (in units of 10(21)POT with the proton energy of 40 GeV), the mass-hierarchy determination with the median sensitivity of 3-5 sigma by the T2KK and 1-4 sigma by the T2KO experiment are expected when sin(2) theta(23) = 0.5, depending on the mass-hierarchy pattern and CP phase. These sensitivities are enhanced (reduced) by 30-40% in Delta chi(2) when sin(2) theta(23) = 0.6 (0.4). The CP phase is measured with the uncertainty of 20 degrees-50 degrees by theT2KKandT2KOusing the nu(mu)-(nu) over bar (mu) focusing beam ratio between 3.5: 1.5 and 1.5: 3.5. These findings indicate that inclusion of the (nu) over bar mu focusing beam improves the sensitivities of the T2KK and T2KO experiments to both the mass-hierarchy determination and the leptonic CP phase measurement simultaneously with the preferred beam ratio being between 3: 2-2.5: 2.5 (x10(21)POT).

  
  

  

• Asymmetric dark matter bound state

  Title	: Asymmetric dark matter bound state
  Journal	: PHYSICAL REVIEW D, 2017

  
  

  논문

  NUMBER	P16027
  AUTHOR	Ko, P.,Kang, Zhaofeng,Li, Jinmian
  TITLE	Asymmetric dark matter bound state
  ARCHIVE	arXiv:1602.08816
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2017
  ABSTRACT	We propose an interesting framework for asymmetric scalar dark matter (ADM), which has novel collider phenomenology in terms of an unstable ADM bound state (ADMonium) produced via Higgs portals. ADMonium is a natural consequence of the basic features of ADM: the (complex scalar) ADM is charged under a dark local U(1)(d) symmetry which is broken at a low scale and provides a light gauge boson X. The dark gauge coupling is strong and then ADM can annihilate away into X-pair effectively. Therefore, the ADM can form a bound state due to its large self-interaction via X mediation. To explore the collider signature of ADMonium, we propose that ADM has a two-Higgs doublet portal. The ADMonium can have a sizable mixing with the heavier Higgs boson, which admits a large cross section of ADMonium production associated with b (b) over bar. The resulting signature at the LHC depends on the decays of X. In this paper we consider a case of particular interest: pp -> b (b) over bar + ADMonium followed by ADMonium -> 2X -> 2e(+)e(-) where the electrons are identified as (un)converted photons. It may provide a competitive explanation to heavy di-photon resonance searches at the LHC.

  
  

  

• Interference effects of two scalar boson propagators on the LHC search for the singlet fermion DM

  Title	: Interference effects of two scalar boson propagators on the LHC search for the singlet fermion DM
  Journal	: PHYSICS LETTERS B, 2017

  
  

  논문

  NUMBER	P16076
  AUTHOR	Ko, P.,Li, Jinmian
  TITLE	Interference effects of two scalar boson propagators on the LHC search for the singlet fermion DM
  ARCHIVE	arXiv:1610.03997
  FILE
  JOURNAL	PHYSICS LETTERS B, 2017
  ABSTRACT	A gauge invariant UV-completion for singlet fermion DM interacting with the standard model (SM) particles involves a new singlet scalar. Therefore the model contains two scalar mediators, mixtures of the SM Higgs boson and a singlet scalar boson. Collider phenomenology of the interference effect between these two scalar propagators is studied in this work. This interference effect can be either constructive or destructive in the DM production cross section depending on both singlet scalar and DM masses, and it will soften the final state jets in the full mass region. Applying the CMS mono-jet search to our model, we find the interference effect plays a very important role in the DM search sensitivity, and the DM production cross section of our model is more than one order of magnitude below the LHC sensitivity at current stage. (C) 2016 The Author(s). Published by Elsevier B.V.

  
  

  

• Higgs-portal assisted Higgs inflation with a sizeable tensor-to-scalar ratio

  Title	: Higgs-portal assisted Higgs inflation with a sizeable tensor-to-scalar ratio
  Journal	: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2017

  
  

  논문

  NUMBER	Q16017
  AUTHOR	Ko, Pyungwon,Kim, Jinsu
  TITLE	Higgs-portal assisted Higgs inflation with a sizeable tensor-to-scalar ratio
  ARCHIVE	1405.1635
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2017
  ABSTRACT	We show that the Higgs portal interactions involving extra dark Higgs field can save generically the original Higgs inflation of the standard model (SM) from the problem of a deep non-SM vacuum in the SM Higgs potential. Specifically, we show that such interactions disconnect the top quark pole mass from inflationary observables and allow multi-dimensional parameter space to save the Higgs inflation, thanks to the additional parameters (the dark Higgs boson mass m(phi), the mixing angle a between the SM Higgs H and dark Higgs Phi, and the mixed quartic coupling) affecting RG-running of the Higgs quartic coupling. The effect of Higgs portal interactions may lead to a larger tensor-to-scalar ratio, 0.08 less than or similar to r less than or similar to 0.1, by adjusting relevant parameters in wide ranges of alpha and m(phi), some region of which can be probed at future colliders. Performing a numerical analysis we find an allowed region of parameters, matching the latest Planck data.

  
  

  

• Simplified DM models with the full SM gauge symmetry: the case of t-channel colored scalar mediators

  Title	: Simplified DM models with the full SM gauge symmetry: the case of t-channel colored scalar mediators
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2017

  
  

  논문

  NUMBER	Q16012
  AUTHOR	Ko, P.,Yokoya, Hiroshi,Natale, Alexander
  TITLE	Simplified DM models with the full SM gauge symmetry: the case of t-channel colored scalar mediators
  ARCHIVE	arXiv:1605.07058
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2017
  ABSTRACT	The general strategy for dark matter (DM) searches at colliders currently relies on simpli fi ed models. In this paper, we propose a new t -channel UV-complete simpli fi ed model that improves the existing simpli fi ed DM models in two important respects: (i) we impose the full SM gauge symmetry including the fact that the left-handed and the righthanded fermions have two independent mediators with two independent couplings, and (ii) we include the renormalization group evolution when we derive the e ff ective Lagrangian for DM-nucleon scattering from the underlying UV complete models by integrating out the t -channel mediators. The fi rst improvement will introduce a few more new parameters compared with the existing simpli fi ed DM models. In this study we look at the e ff ect this broader set of free parameters has on direct detection and the mono-X + MET (X = jet, W; Z) signatures at 13TeV LHC while maintaining gauge invariance of the simplifi ed model under the full SM gauge group. We fi nd that the direct detection constraints require DM masses less than 10 GeV in order to produce phenomenologically interesting collider signatures. Additionally, for a fi xed mono-W cross section it is possible to see very large di ff erences in the mono-jet cross section when the usual simpli fi ed model assumptions are loosened and isospin violation between RH and LH DM-SM quark couplings are allowed.

  
  

  

• Diphoton excess at 750 GeV in leptophobic U(1) model inspired by E-6 GUT

  Title	: Diphoton excess at 750 GeV in leptophobic U(1) model inspired by E-6 GUT
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2016

  
  

  논문

  NUMBER	P16002
  AUTHOR	Ko, P.
  TITLE	Diphoton excess at 750 GeV in leptophobic U(1) model inspired by E-6 GUT
  ARCHIVE	arXiv:1601.00586
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2016
  ABSTRACT	We discuss the 750 GeV diphoton excess at the LHCA@13TeV in the framework of leptophobic U(1) model inspired by E-6 grand unified theory (GUT). In this model, the Standard Model (SM) chiral fermions carry charges under extra U(1) gauge symmetry which is spontaneously broken by a U(1)-charged singlet scalar (Phi)). In addition, extra quarks and leptons are introduced to achieve the anomaly -free conditions, which is a natural consequence of the assumed E-6 GUT. These new fermions are vectorlike under the SM gauge group but chiral under new U(1), and their masses come entirely from the nonzero vacuum expectation value of Phi through the Yukawa interactions. Then, the CP-even scalar h(Phi) from Phi can be produced at the LHC by the gluon fusion and decay to the diphoton via the one -loop diagram involving the extra quarks and leptons, and can be identified as the origin of diphoton excess at 750 GeV. In this model, h(Phi), can decay into a pair of dark matter particles as well as a pair of scalar bosons, thereby a few tens of the decay width may be possible.

  
  

  

• Light dark photon and fermionic dark radiation for the Hubble constant and the structure formation

  Title	: Light dark photon and fermionic dark radiation for the Hubble constant and the structure formation
  Journal	: PHYSICS LETTERS B, 2016

  
  

  논문

  NUMBER	P16063
  AUTHOR	Ko, P.,Tang, Yong
  TITLE	Light dark photon and fermionic dark radiation for the Hubble constant and the structure formation
  ARCHIVE	1608.01083
  FILE
  JOURNAL	PHYSICS LETTERS B, 2016
  ABSTRACT	Motivated by the tensions in the Hubble constant H-0 and the structure growth sigma(8) between Planckresults and other low redshift measurements, we discuss some cosmological effects of a dark sector model in which dark matter (DM) interacts with fermionic dark radiation (DR) through a light gauge boson (dark photon). Such kind of models are very generic in particle physics with a dark sector with dark gauge symmetries. The effective number of neutrinos is increased by delta N-eff similar to 0.5 due to light dark photon and fermionic DR, thereby resolving the conflicts in H-0. The elastic scattering between DM and DR induces suppression for DMs density perturbation, but without acoustic oscillations. For weakly-interacting DM around 100GeV, the new gauge coupling should be similar to 10(-4) to have sizable effect on matter power spectrum in order to relax the tension in s8. (C) 2016 The Author(s). Published by Elsevier B.V.

  
  

  

• Flavor SU (3) properties of beauty tetraquark states with three different light quarks

  Title	: Flavor SU (3) properties of beauty tetraquark states with three different light quarks
  Journal	: PHYSICS LETTERS B, 2016

  
  

  논문

  NUMBER	P16022
  AUTHOR	Ko, Pyungwon
  TITLE	Flavor SU (3) properties of beauty tetraquark states with three different light quarks
  ARCHIVE	arXiv:1603.02915
  FILE
  JOURNAL	PHYSICS LETTERS B, 2016
  ABSTRACT	Beauty tetraquark states X ((b) over barq q (q) over bar) composed of (b) over bar su (d) over bar, (b) over bar ds (u) over bar, and (b) over bar ud (s) over bar, are unique that all the four valence quarks are different. Although the claim of existence of the first two states by DO was not confirmed by data from LHCb, the possibility of such states still generated a lot of interests and should be pursued further. Non-observation of X((b) over barqq (q) over bar) states by LHCb may be just due to a still lower production rate than the limit of LHCb or at some different mass ranges. In this work we use light quark SU(3) flavor symmetry as guideline to classify symmetry properties of beauty tetraquark states. The multiplets which contain states with three different light quarks must be one of (6) over bar or 15 of SU(3) representations. We study possible decays of such a tetraquark state into a B meson and a light pseudoscalar octet meson by constructing a leading order chiral Lagrangian, and also provide search strategies to determine whether a given tetraquark state of this type belongs to (6) over bar or 15. If X((b) over barqq (q) over bar) belongs to 15, there are new doubly charged tetraquark states (b) over bar uu (d) over bar and (b) over bar uu (s) over bar. (C) 2016 The Authors. Published by Elsevier B.V.

  
  

  

• Higgs precision study of the 750 GeV diphoton resonance and the 125 GeV standard model Higgs boson with Higgs-singlet mixing

  Title	: Higgs precision study of the 750 GeV diphoton resonance and the 125 GeV standard model Higgs boson with Higgs-singlet mixing
  Journal	: PHYSICAL REVIEW D, 2016

  
  

  논문

  NUMBER	P16001
  AUTHOR	Ko, P.
  TITLE	Higgs precision study of the 750 GeV diphoton resonance and the 125 GeV standard model Higgs boson with Higgs-singlet mixing
  ARCHIVE	arXiv:1512.07853
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2016
  ABSTRACT	We interpret the potential observation of the 750 GeV diphoton resonance at the LHC in models, in which an SU(2) isospin-singlet scalar boson mixes with the standard model (SM) Higgs boson through an angle alpha. Allowing the singlet scalar boson to have renormalizable couplings to vectorlike leptons and quarks and introducing sizable decay width of the 750 GeV diphoton resonance into non-SMparticles such as dark matters, we can explain the large production cross section sigma(H-2) x B(H-2 -> gamma gamma) as well as the apparent large total width of the boson without conflicts from the results obtained by previous global fits to the SM Higgs boson data.

  
  

  

• AdS/QCD approach to the scale-invariant extension of the standard model with a strongly interacting hidden sector

  Title	: AdS/QCD approach to the scale-invariant extension of the standard model with a strongly interacting hidden sector
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2016

  
  

  논문

  NUMBER	P16045
  AUTHOR	Ko, Pyungwon,Hatanaka, Hisaki
  TITLE	AdS/QCD approach to the scale-invariant extension of the standard model with a strongly interacting hidden sector
  ARCHIVE	arXiv:1606.02969
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2016
  ABSTRACT	In this paper, we revisit a scale-invariant extension of the standard model (SM) with a strongly interacting hidden sector within AdS/QCD approach. Using the AdS/QCD, we reduce the number of input parameters to three, i.e. hidden pion decay constant, hidden pion mass and tan beta that is defined as the ratio of the vacuum expectation values (VEV) of the singlet scalar field and the SM Higgs boson. As a result, our model has sharp predictability. We perform the phenomenological analysis of the hidden pions which is one of the dark matter (DM) candidates in this model. With various theoretical and experimental constraints we search for the allowed parameter space and find that both resonance and non-resonance solutions are possible. Some typical correlations among various observables such as thermal relic density of hidden pions, Higgs boson signal strengths and DM-nucleon cross section are investigated. We provide some benchmark points for experimental tests.

  
  

  

• Top-philic scalar Dark Matter with a vector-like fermionic top partner

  Title	: Top-philic scalar Dark Matter with a vector-like fermionic top partner
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2016

  
  

  논문

  NUMBER	P16044
  AUTHOR	Ko, Pyungwon,Baek, Seungwon,Wu, Peiwen
  TITLE	Top-philic scalar Dark Matter with a vector-like fermionic top partner
  ARCHIVE	arXiv:1606.00072
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2016
  ABSTRACT	We consider a simple extension of the Standard Model with a scalar top-philic Dark Matter (DM) S coupling, apart from the Higgs portal, exclusively to the right-handed top quark t (R) and a colored vector-like top partner T with a Yukawa coupling y (ST) which we call the topVL portal. When the Higgs portal is closed and y (ST) is perturbative (less than or similar to 1), T S -> (W (+) b, gt), SS -> t (t) over bar and T (T) over bar -> (q (q) over bar, gg) provide the dominant (co) annihilation contributions to obtain Omega(DM) h (2) similar or equal to 0.12 in light, medium and heavy DM mass range, respectively. However, large yST similar to O(10) can make SS -> gg dominate via the loop-induced coupling C (SSgg) in the m (S) < m (t) region. In this model it is the C (SSgg) coupling that generates DM-nucleon scattering in the direct detection, which can be large and simply determined by Omega(DM) h (2) similar or equal to 0.12 when SS -> gg dominates the DM annihilation. The current LUX results can exclude the SS -> gg dominating scenario and XENON-1T experiment may further test y (ST) greater than or similar to 1, and 0.5 less than or similar to y (ST) less than or similar to 1 may be covered in the future LUX-ZP experiment. The current indirect detection results from Fermi gamma-ray observations can also exclude the SS -> gg dominating scenario and are sensitive to the heavy DM mass region, of which the improved sensitivity by one order will push DM mass to be above 400, 600, 1000 GeV for y (ST) = 0.3, 0.5, 1.0, respectively. T (T) over bar pair produced at the hadron collider will decay 100% into t (t) over bar + is not an element of(T) signal when kinematically open. The latest ATLAS 13 TeV 13.2 fb(-1) data can excluded m (T) between 300 (650) and 1150 (1100) GeV for m (S) =40 (400) GeV and the exclusion region can reach up to m(S) similar to 500 GeV.

  
  

  

• SU(2)(L) x SU(2)(R) minimal dark matter with 2 TeV W

  Title	: SU(2)(L) x SU(2)(R) minimal dark matter with 2 TeV W
  Journal	: PHYSICS LETTERS B, 2016

  
  

  논문

  NUMBER	P15057
  AUTHOR	Ko, P.,Nomura, Takaaki
  TITLE	SU(2)(L) x SU(2)(R) minimal dark matter with 2 TeV W
  ARCHIVE	arXiv:1510.07872
  FILE
  JOURNAL	PHYSICS LETTERS B, 2016
  ABSTRACT	We construct the minimal dark matter models in the left-right symmetric extensions of the standard model (SM), where the gauge symmetry SU(3)(C) x SU(2)(L) x SU(2)(R) x U(1)(B-L) is broken into its subgroup SU(3)(C) x U(1)(em) by nonzero VEVs of a SU(2)(R) doublet H-R and a SU(2)(L) x SU(2)(R) bidoublet H. A possible candidate of dark matter is explored in the framework of minimal dark matter considering SU(2)(L,R) multiplet scalar bosons and fermions. Then we focus on SU(2)(R) quintuplet fermions with B - L charges 0, 2 and 4 as the minimal dark matter candidates and investigate their phenomenology. We show that the dark matter in the model can provide observed relic density with 2 TeV W boson which is motivated by the ATLAS diboson excess and CMS eejj excess. The possible mass of dark matter is predicted for each B - L charge. We then estimate the scattering cross section of dark matter with nucleon and production cross section of charged components in the quintuplets at the LHC. (C) 2015 The Authors. Published by Elsevier B.V.

  
  

  

• Confronting a new three-loop seesaw model with the 750 GeV diphoton excess

  Title	: Confronting a new three-loop seesaw model with the 750 GeV diphoton excess
  Journal	: PHYSICAL REVIEW D, 2016

  
  

  논문

  NUMBER	P16018
  AUTHOR	Ko, P.,Nomura, Takaaki
  TITLE	Confronting a new three-loop seesaw model with the 750 GeV diphoton excess
  ARCHIVE	arXiv:1602.07214
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2016
  ABSTRACT	We propose a new type of radiative neutrino model with a local dark U(1) symmetry, where neutrino masses are induced at the three-loop level, and discuss the muon anomalous magnetic moment and dark matter candidates therein. By allowing hypercharges larger than 3/2 for new fields that contribute to the neutrino masses and making them decay into the standard-model fields appropriately, we introduce a lot of new particles with multiple electrical charges in a natural manner. As a byproduct, we can accommodate the 750 GeV diphoton excess depending on the hypercharge quantum numbers of new fields responsible for the neutrino masses at the three-loop level.

  
  

  

• Dark sector shining through 750 GeV dark Higgs boson at the LHC

  Title	: Dark sector shining through 750 GeV dark Higgs boson at the LHC
  Journal	: PHYSICS LETTERS B, 2016

  
  

  논문

  NUMBER	P16006
  AUTHOR	Ko, P.,Nomura, Takaaki
  TITLE	Dark sector shining through 750 GeV dark Higgs boson at the LHC
  ARCHIVE	arXiv:1601.02490
  FILE
  JOURNAL	PHYSICS LETTERS B, 2016
  ABSTRACT	We consider a dark sector with SU(3)(C) x U(1)(Y) x U(1)(X) and three families of dark fermions that are chiral under dark U(1)(X) gauge symmetry, whereas scalar dark matter Xis the SM singlet. U(1)(X) dark symmetry is spontaneously broken by nonzero VEV of dark Higgs field , generating the masses of dark fermions and dark photon Z. The resulting dark Higgs boson phi can be produced at the LHC by dark quark loop (involving 3 generations) and will decay into a pair of photon through charged dark fermion loop. Its decay width can be easily similar to 45 GeV due to its possible decays into a pair of dark photon, which is not strongly constrained by the current LHC searches pp -> phi -> ZZ followed by Z decays into the SM fermion pairs. The scalar DM can achieve thermal relic density without conflict with direct detection bound or the invisible phi decay into a pair of DM. (C) 2016 The Author(s). Published by Elsevier B.V.

  
  

  

• Search for Higgs portal DM at the ILC

  Title	: Search for Higgs portal DM at the ILC
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2016

  
  

  논문

  NUMBER	Q16009
  AUTHOR	Ko, P.,Yokoya, Hiroshi
  TITLE	Search for Higgs portal DM at the ILC
  ARCHIVE	arXiv:1603.04737
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2016
  ABSTRACT	Higgs portal dark matter (DM) models are simple interesting and viable DM models. There are three types of the models depending on the DM spin: scalar, fermion and vector DM models. In this paper, we consider renormalizable, unitary and gauge invariant Higgs portal DM models, and study how large parameter regions can be surveyed at the International Linear Collider (ILC) experiment at root s = 500 GeV. For the Higgs portal singlet fermion and vector DM cases, the force mediator involves two scalar propagators, the SM-like Higgs boson and the dark Higgs boson. We show that their interference generates interesting and important patterns in the mono-Z plus missing E-T signatures at the ILC, and the results are completely different from those obtained from the Higgs portal DM models within the effective field theories. In addition, we show that it would be possible to distinguish the spin of DM in the Higgs portal scenarios, if the shape of the recoil-mass distribution is observed. We emphasize that the interplay between these collider observations and those in the direct detection experiments has to be performed in the model with renomalizability and unitarity to combine the model analyses in different scales.

  
  

  

• Beyond the dark matter effective field theory and a simplified model approach at colliders

  Title	: Beyond the dark matter effective field theory and a simplified model approach at colliders
  Journal	: PHYSICS LETTERS B, 2016

  
  

  논문

  NUMBER	P15029
  AUTHOR	Ko, P.,Baek, Seungwon
  TITLE	Beyond the dark matter effective field theory and a simplified model approach at colliders
  ARCHIVE	arXiv:1506.06556
  FILE
  JOURNAL	PHYSICS LETTERS B, 2016
  ABSTRACT	Direct detection of and LHC search for the singlet fermion dark matter (SFDM) model with Higgs portal interaction are considered in a renormalizable model where the full Standard Model (SM) gauge symmetry is imposed by introducing a singlet scalar messenger. In this model, direct detection is described by an effective operator m(q)(q) over barq (chi) over bar chi as usual, but the full amplitude for monojet + is not an element of(T) involves two intermediate scalar propagators, which cannot be seen within the effective field theory (EFT) or in the simplified model without the full SM gauge symmetry. We derive the collider bounds from the ATLAS monojet + is not an element of(T) as well as the CMS t (t) over bar + is not an element of(T) data, finding out that the bounds and the interpretation of the results are completely different from those obtained within the EFT or simplified models. It is pointed out that it is important to respect unitarity, renormalizability and local gauge invariance of the SM. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license

  
  

  

• New avenues to heavy right-handed neutrinos with pair production at hadronic colliders

  Title	: New avenues to heavy right-handed neutrinos with pair production at hadronic colliders
  Journal	: PHYSICAL REVIEW D, 2016

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.,Kang, Zhaofeng
  TITLE	New avenues to heavy right-handed neutrinos with pair production at hadronic colliders
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2016
  ABSTRACT	In many models incorporating the type-I seesaw mechanism, the right-handed neutrino (N) couples to heavy vector/scalar bosons and thereby has resonant pair production. It has barely received attention thus far; however, it may provide the best avenue to probe TeV scale N without requiring anomalously large mixing between N and the active neutrino nu(L). In this paper we explore the discovery prospects of (mainly heavy) N pair production at the 14 TeV LHC and future 100 TeV pp collider, based on the three signatures: (1) trilepton from N (-> lW(l)) N (-> lW(h)) with W-l/h being the leptonically/hadronically decaying W; (2) boosted di-Higgs boson plus E-T from N (-> nu(L)h) N (-> nu(L)h); (3) a single boosted Higgs boson with leptons and E-T from N (-> lW(l)) N (-> nu(L)h). At the 100 TeV collider, we also consider the situation when the Higgs boson is overboosted, thus losing its jet substructure. Interpreting our tentative results in the benchmark model, the local B-L model, we find that the (multi-) TeV scale N can be probed at the (100) 14 TeV colliders.

  
  

  

• New Physics Opportunities in the Boosted Di-Higgs-Boson Plus Missing Transverse Energy Signature

  Title	: New Physics Opportunities in the Boosted Di-Higgs-Boson Plus Missing Transverse Energy Signature
  Journal	: PHYSICAL REVIEW LETTERS, 2016

  
  

  논문

  NUMBER	P15028
  AUTHOR	Ko, P.,Kang, Zhaofeng
  TITLE	New Physics Opportunities in the Boosted Di-Higgs-Boson Plus Missing Transverse Energy Signature
  ARCHIVE	arXiv:1504.04128
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2016
  ABSTRACT	The Higgs field in the standard model may couple to new physics sectors related to dark matter and/or massive neutrinos. In this Letter we propose a novel signature, the boosted di-Higgs-boson plus E-T (which is either a dark matter or neutrino), to probe those new physics sectors. In a large class of models, in particular, the supersymmetric standard models and low scale seesaw mechanisms, this signature can play a key role. The signature has a clear background, and at the root s = 14 TeV high luminosity LHC, we can probe it with a production rate as low as similar to 0.1 fb. We apply it to benchmark models, supersymmetry in the bino-Higgsino limit, the canonical seesaw model, and the little Higgs model, finding that the masses of the Higgsino, right-handed neutrino, and heavy vector boson can be probed up to similar to 500, 650, and 900 GeV, respectively.

  
  

  

• Phenomenology of dark matter in chiral U(1)(X) dark sector

  Title	: Phenomenology of dark matter in chiral U(1)(X) dark sector
  Journal	: PHYSICAL REVIEW D, 2016

  
  

  논문

  NUMBER	P16053
  AUTHOR	Ko, P.,Nomura, Takaaki
  TITLE	Phenomenology of dark matter in chiral U(1)(X) dark sector
  ARCHIVE	arXiv:1607.06218
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2016
  ABSTRACT	We consider dark matter physics in a model for the dark sector with extra dark U(1)(X) gauge symmetry. The dark sector is composed of exotic fermions that are charged under both dark U(1)(X) and the standard model SU(3)(C) xU(1)(Y) gauge groups, as well as standard model singlet complex scalars Phi and X with nonzero U(1)(X) charge. In this model, there are two dark matter candidates-a scalar and a fermion-both of which are stabilized by accidental Z(2) symmetry. Their thermal relic density, and direct and indirect detection constraints are discussed in detail and we search for the parameter space of the model accommodating dark matter observations. We also discuss constraints from diphoton resonance searches associated with the scalar field which breaks the dark U(1)(X), in a way consistent with dark matter physics. In addition, implications for collider physics are discussed, focusing on the production cross section of the scalar boson.

  
  

  

• Dark Higgs channel for Fermi GeV gamma-ray excess

  Title	: Dark Higgs channel for Fermi GeV gamma-ray excess
  Journal	: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2016

  
  

  논문

  NUMBER	P15027
  AUTHOR	Ko, P.,Tang, Yong
  TITLE	Dark Higgs channel for Fermi GeV gamma-ray excess
  ARCHIVE	arXiv:1504.03908
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2016
  ABSTRACT	Dark Higgs is very generic in dark matter models where DM is stabilized by some spontaneously broken dark gauge symmetries. Motivated by tentative GeV scale gamma-ray excess from the galactic center (GC), we investigate a scenario where a pair of dark matter X annihilates into a pair of dark Higgs H-2, which subsequently decays into standard model particles through its mixing with SM Higgs boson. Besides the two-body decay of H-2, we also include multibody decay channels of the dark Higgs. We find that the best-fit point is around M-X similar or equal to 95.0 GeV, M-H2 similar or equal to 86.7 GeV, sigma nu similar or equal to 4.0 x 10(-26)cm(3)/s and gives a p-value similar or equal to 0.40. Implication of this result is described in the context of dark matter models with dark gauge symmetries. Since such a dark Higgs boson is very difficult to produce at colliders, indirect DM detections of cosmic gamma-rays could be an important probe of dark sectors, complementary to collider searches.

  
  

  

• Bounds on Higgs-portal models from the LHC Higgs data

  Title	: Bounds on Higgs-portal models from the LHC Higgs data
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2015

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.
  TITLE	Bounds on Higgs-portal models from the LHC Higgs data
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2015
  ABSTRACT	In a number of Higgs-portal models, an SU(2) isospin-singlet scalar boson generically appears at the electroweak scale and can mix with the Standard Model (SM) Higgs boson with a mixing angle alpha. This singlet scalar boson can have renormalizable couplings to a pair of dark matter particles, vector-like leptons or quarks, or new gauge bosons, thereby modifying the Higgs signal strengths in a nontrivial way. In this work, we perform global fits to such models using the most updated LHC Higgs-boson data and discuss the corresponding implications on Higgs-portal-type models. In particular we find that the current LHC Higgs-boson data slightly favors the SM over the Higgs-portal singlet-scalar models, which has to be further examined using the upcoming LHC Higgs-boson data. Finally, without non-SM particles contributing to the H gamma gamma and Hgg vertices, the Higgs-portal models are constrained as follows: cos alpha greater than or similar to 0.86 and Delta Gamma(tot) less than or similar to 1.24 MeV at 95% confidence level (CL).

  
  

  

• Higgs and dark matter physics in the type-II two-Higgs-doublet model inspired by E-6 GUT

  Title	: Higgs and dark matter physics in the type-II two-Higgs-doublet model inspired by E-6 GUT
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2015

  
  

  논문

  NUMBER	P15006
  AUTHOR	Ko, P.,Yu, Chaehyun
  TITLE	Higgs and dark matter physics in the type-II two-Higgs-doublet model inspired by E-6 GUT
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2015
  ABSTRACT	We study Higgs and dark matter physics in the type-II two-Higgs-doublet model (2HDM) with an extra U(1)(H) gauge symmetry, inspired by the E-6 grand unified theory (GUT). From the viewpoint of the bottom-up approach, the additional U(1)(H) gauge symmetry plays a crucial role in avoiding the tree-level flavor changing neutral currents mediated by neutral Higgs bosons in general 2HDMs. In the model with U(1)(H) gauge symmetry, which has Type-II Yukawa couplings, we have to introduce additional chiral fermions that are charged under the U(1)(H) gauge symmetry as well as under the Standard-Model (SM) gauge symmetry in order to cancel chiral gauge anomalies. For the U(1)(H) charge assignment and the extra matters, we adopt the ones inspired by the E-6 GUT: the extra quark-like and lepton-like fermions with the non-trivial U(1)(H) charges. We discuss their contributions to the physical observables, such as the measurements of Higgs physics and electro-weak interactions, and investigate the consistency with the experimental results. Furthermore, we could find extra neutral particles like the SM neutrinos after the electro-weak symmetry breaking, and they could be stable, because of the remnant symmetry after U(1)(H) symmetry breaking. We also discuss the thermal relic density and the (in)direct-detections of this dark matter candidate.

  
  

  

• IceCube events from heavy DM decays through the right-handed neutrino portal

  Title	: IceCube events from heavy DM decays through the right-handed neutrino portal
  Journal	: PHYSICS LETTERS B, 2015

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.,Tang, Yong
  TITLE	IceCube events from heavy DM decays through the right-handed neutrino portal
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, 2015
  ABSTRACT	The recently observed IceCube PeV events could be due to heavy dark matter (DM) decay. In this paper, we propose a simple DM model with extra U(1)(X) gauge symmetry and bridge it with standard model particles through heavy right-handed neutrino. The Dirac fermion DM chi with mass similar to 5PeV can dominantly decay into a dark Higgs (phi), the SM Higgs (h) and a neutrino (nu). If the lifetime of chi is similar to O(10(28)) s, the resulting neutrino flux can fit data consistently. The neutrino flux from chi ->phi h nu in our model is softer than the one predicted from chi ->nu h, for example. We also discuss a possible mechanism to produce DM with the right relic abundance. (C) 2015 The Authors. Published by Elsevier B.V.

  
  

  

• AMS02 positron excess from decaying fermion DM with local dark gauge symmetry

  Title	: AMS02 positron excess from decaying fermion DM with local dark gauge symmetry
  Journal	: PHYSICS LETTERS B, 2015

  
  

  논문

  NUMBER	P14076
  AUTHOR	Ko, P.,Tang, Young
  TITLE	AMS02 positron excess from decaying fermion DM with local dark gauge symmetry
  ARCHIVE	arXiv:1410.7657
  FILE
  JOURNAL	PHYSICS LETTERS B, 2015
  ABSTRACT	Positron excess observed by PAMELA, Fermi and AMS02 may be due to dark matter (DM) pair annihilation or decay dominantly into muons. In this paper, we consider a scenario with thermal fermionic DM (chi) with mass similar to O(1-2) TeV decaying into a dark Higgs (phi) and an active neutrino (nu(a)) instead of the SM Higgs boson and nu(a). We first present a renormalizable model for this scenario with local dark U(1)(X) gauge symmetry, in which the DM chi can be thermalized by Higgs portal and the gauge kinetic mixing. Assuming the dark Higgs (phi) mass is in the range 2m(mu) < m(phi) < 2m(pi)0, the positron excess can be fit if a proper background model is used, without conflict with constraints from antiproton and gamma-ray fluxes or direct detection experiments. Also, having such a light dark Higgs, the self-interaction of DM can be enhanced to some extent, and three puzzles in the CDM paradigm can be somewhat relaxed. (C) 2015 The Authors. Published by Elsevier B. V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

  
  

  

• Local Z(2) scalar dark matter model confronting galactic GeV-scale gamma-ray

  Title	: Local Z(2) scalar dark matter model confronting galactic GeV-scale gamma-ray
  Journal	: PHYSICS LETTERS B, 2015

  
  

  논문

  NUMBER	P17135
  AUTHOR	Ko, P.,Baek, Seungwon,Park, Wan-Il
  TITLE	Local Z(2) scalar dark matter model confronting galactic GeV-scale gamma-ray
  ARCHIVE	arXiv:1407.6588
  FILE
  JOURNAL	PHYSICS LETTERS B, 2015
  ABSTRACT	We present a scalar dark matter (DM) model where DM (X-I) is stabilized by a local Z(2) symmetry originating from a spontaneously broken local dark U(1)(X). Compared with the usual scalar DM with a global Z(2) symmetry, the local Z(2) model possesses three new extra fields, dark photon 21, dark Higgs phi and the excited partner of scalar DM (X-R), with the kinetic mixing and Higgs portal interactions dictated by local dark gauge invariance. The resulting model can accommodate thermal relic density of scalar DM without conflict with the invisible Higgs branching ratio and the bounds from DM direct detections, thanks to the newly opened channels, XIXI -> ZZ, phi phi. In particular, due to the new particles, the GeV scale gamma-ray excess from the Galactic Center (GC) can be originated from the decay of dark Higgs boson which is produced in DM annihilations. (C) 2015 The Authors. Published by Elsevier B.V.

  
  

  

• Natural X-ray lines from the low scale supersymmetry breaking

  Title	: Natural X-ray lines from the low scale supersymmetry breaking
  Journal	: PHYSICS LETTERS B, 2015

  
  

  논문

  NUMBER	P14025
  AUTHOR	Ko, P.,Kang, Zhaofeng
  TITLE	Natural X-ray lines from the low scale supersymmetry breaking
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, 2015
  ABSTRACT	In the supersymmetric models with low scale supersymmetry (SUSY) breaking where the gravitino mass is around keV, we show that the 3.5 keV X-ray lines can be explained naturally through several different mechanisms: (I) a keV scale dark gaugino plays the role of sterile neutrino in the presence of bilinear R-parity violation. Because the light dark gaugino obtains Majorana mass only via gravity mediation, it is a decaying warm dark matter (DM) candidate; (II) the compressed cold DM states, whose mass degeneracy is broken by gravity mediated SUSY breaking, emit such a line via the heavier one decay into the lighter one plus photon(s). A highly supersymmetric dark sector may readily provide such kind of system; (III) the light axino, whose mass again is around the gravitino mass, decays to neutrino plus gamma in the R-parity violating SUSY. Moreover, we comment on dark radiation from dark gaugino. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.

  
  

  

• Galactic center gamma-ray excess in hidden sector DM models with dark gauge symmetries: local Z(3) symmetry as an example

  Title	: Galactic center gamma-ray excess in hidden sector DM models with dark gauge symmetries: local Z(3) symmetry as an example
  Journal	: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2015

  
  

  논문

  NUMBER	P14074
  AUTHOR	Ko, P.,Tang, Yong
  TITLE	Galactic center gamma-ray excess in hidden sector DM models with dark gauge symmetries: local Z(3) symmetry as an example
  ARCHIVE	arXiv:1407.5492
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2015
  ABSTRACT	We show that hidden sector dark matter (DM) models with local dark gauge symmetries make a natural playground for the possible gamma-ray excess from the galactic center (GC). We first discuss in detail the GC gamma-ray excess in a scalar dark matter (DM) model with local Z(3) symmetry which was recently proposed by the present authors. Within this model, scalar DM with mass 30-70 GeV is allowed due to the newly-opened (semi-)annihilation channels of a DM pair into dark Higgs phi and/or dark photon Z pair, and the gamma-ray spectrum from the GC can be fit within this model. Then we argue that the GC gamma ray excess can be easily accommodated within hidden sector dark matter models where DM is stabilized by local gauge symmetries, due to the presence of dark Higgs (and also dark photon for Abelian dark gauge symmetry).

  
  

  

• Accidental dark matter: Case in the scale invariant local B - L model

  Title	: Accidental dark matter: Case in the scale invariant local B - L model
  Journal	: PHYSICAL REVIEW D, 2015

  
  

  논문

  NUMBER	P15007
  AUTHOR	Ko, P.,Kang, Zhaofeng
  TITLE	Accidental dark matter: Case in the scale invariant local B - L model
  ARCHIVE	arXiv:1502.00508
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2015
  ABSTRACT	We explore the idea of accidental dark matter (aDM) stability in the scale invariant local U(1)(B-L) model, which is a theory for neutrino and at the same time radiatively breaks scale invariance via quantum mechanical dynamics in the U(1)(B-L) sector. A real singlet scalar can be accidental DM with an accidental Z(2), by virtue of both extended symmetries. A U(1)(B-L) charged complex scalar can also be a viable accidental DM due to an accidental (or remanent) Z(3). They can reproduce correct relic density via the annihilations through the conventional Higgs portal or dark Higgs portal. The dark Higgs portal scenario is in tension with the LHC bound on Z(B-L), and only heavy DM of a few TeVs can have correct relic density. In particular, DM may trigger classical scale invariance spontaneous breaking. The situation is relaxed significantly in the Z(3) case due to the effective semiannihilation mode, and then light DM can be accommodated easily. In addition, the Z(3) model can accommodate the GeV scale gamma-ray excess from the Galactic center via semiannihilation into pseudo-Goldstone boson. The best fit is achieved at a DM about 52 GeV, with an annihilation cross section consistent with the thermal relic density. The invisible Higgs branching ratio is negligible because the Higgs portal quartic coupling is very small lambda(h phi) less than or similar to 10(-3).

  
  

  

• nu Lambda MDM: A model for sterile neutrino and dark matter reconciles cosmological and neutrino oscillation data after BICEP2

  Title	: nu Lambda MDM: A model for sterile neutrino and dark matter reconciles cosmological and neutrino oscillation data after BICEP2
  Journal	: PHYSICS LETTERS B, 2014

  
  

  논문

  NUMBER	P14026
  AUTHOR	Ko, P.,Tang, Yong
  TITLE	nu Lambda MDM: A model for sterile neutrino and dark matter reconciles cosmological and neutrino oscillation data after BICEP2
  ARCHIVE	arXiv:1404.0236
  FILE
  JOURNAL	PHYSICS LETTERS B, 2014
  ABSTRACT	We propose an ultraviolet complete theory for cold dark matter (CDM) and sterile neutrinos that can accommodate both cosmological data and neutrino oscillation experiments within 1 sigma level. We assume a new U(1)(X) dark gauge symmetry which is broken at similar to O(MeV) scale resulting light dark photon. Such a light mediator for DMs self-scattering and scattering-off sterile neutrinos can resolve three controversies for cold DM on small cosmological scales: cusp vs. core, too-big-to-fail and missing satellites. We can also accommodate similar to O(1) eV scale sterile neutrinos as the hot dark matter (HDM) and can fit some neutrino anomalies from neutrino oscillation experiments within 1 sigma. Finally, the right amount of HDM can make a sizable contribution to dark radiation, and also helps to reconcile the tension between the data on the tensor-to-scalar ratio reported by Planck and BICEP2 Collaborations. (C) 2014 The Authors. Published by Elsevier B.V.

  
  

  

• Dark matter and dark force in the type-I inert 2HDM with local U(1)(H) gauge symmetry

  Title	: Dark matter and dark force in the type-I inert 2HDM with local U(1)(H) gauge symmetry
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2014

  
  

  논문

  NUMBER	P14030
  AUTHOR	Ko, P.,Yu, Chaehyun
  TITLE	Dark matter and dark force in the type-I inert 2HDM with local U(1)(H) gauge symmetry
  ARCHIVE	1405.2138
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2014
  ABSTRACT	We discuss dark matter (DM) physics in the Type-I inert two-Higgs-doublet model (2HDM) with local U(1) H Higgs gauge symmetry, which is assigned to the extra Higgs doublet in order to avoid the Higgs-mediated flavor problems. In this gauged inert DM setup, a U(1)(H)-charged scalar Phi is also introduced to break U(1)(H) spontaneously through its nonzero vacuum expectation value (VEV), , and then the remnant discrete subgroup appears according to the U(1)(H) charge assignment of Phi. The U(1)(H)-charged Higgs doublet does not have Yukawa couplings with the Standard-Model (SM) fermions, and its lightest neutral scalar component H is stable because of the remnant discrete symmetry. In order to suppress a too large Z-exchange diagram contribution in DM direct detection experiments, we have to introduce a non-renormalizable operator which can be generated by integrating out an extra heavy scalar. With these new particles contents, we first investigate the constraint on the U(1)(H) gauge interaction, especially through the kinetic and mass mixing between the SM gauge bosons and the extra gauge boson. Then we discuss dark matter physics in our 2HDM: thermal relic density, and direct/indirect detections of dark matter. The additional U(1) (H) gauge interaction plays a crucial role in reducing the DM thermal relic density. The most important result within the inert DM model with local U(1)(H) symmetry is that similar to O(10) GeV dark matter scenario, which is strongly disfavored in the usual Inert Doublet Model (IDM) with Z(2) symmetry, is revived in our model because of newly open channels, HH -> Z(H)Z(H), Z(H)Z. Exotic Higgs decays, h -> Z(H)Z(H), ZZ(H), would be distinctive signatures of the inert 2HDM with local U(1)(H) symmetry.

  
  

  

• Hidden sector monopole, vector dark matter and dark radiation with Higgs portal

  Title	: Hidden sector monopole, vector dark matter and dark radiation with Higgs portal
  Journal	: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2014

  
  

  논문

  NUMBER	P13060
  AUTHOR	Ko, P.,Baek, Seungwon,Park, Wan-Il
  TITLE	Hidden sector monopole, vector dark matter and dark radiation with Higgs portal
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2014
  ABSTRACT	We show that the t Hooft-Polyakov monopole model in the hidden sector with Higgs portal interaction makes a viable dark matter model, where monopole and massive vector dark matter (VDM) are stable due to topological conservation and the unbroken subgroup U(1)(X). We show that, even though observed CMB data requires the dark gauge coupling to be quite small, a right amount of VDM thermal relic can be obtained via s-channel resonant annihilation for the mass of VDM close to or smaller than the half of SM higgs mass, thanks to Higgs portal interaction. Monopole relic density turns out to be several orders of magnitude smaller than the observed dark matter relic density. Direct detection experiments, particularly, the projected XENON1T experiment, may probe the parameter space where the dark Higgs is lighter than less than or similar to 50 GeV. In addition, the dark photon associated with the unbroken U(1)(X) contributes to the radiation energy density at present, giving Delta N-eff(nu) similar to 0.1 as the extra relativistic neutrino species.

  
  

  

• Can Zee-Babu model implemented with scalar dark matter explain both Fermi-LAT 130 GeV gamma-ray excess and neutrino physics?

  Title	: Can Zee-Babu model implemented with scalar dark matter explain both Fermi-LAT 130 GeV gamma-ray excess and neutrino physics?
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2014

  
  

  논문

  NUMBER	P12056
  AUTHOR	Ko, P.,Baek, Seungwon,Senahaa, Eibun,Okada, Hiroshi
  TITLE	Can Zee-Babu model implemented with scalar dark matter explain both Fermi-LAT 130 GeV gamma-ray excess and neutrino physics?
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2014
  ABSTRACT	We extend the Zee-Babu model for the neutrino masses and mixings by first incorporating a scalar dark matter X with Z(2) symmetry and then X and a dark scalar phi with global U(1) symmetry. In the latter scenario the singly and doubly charged scalars that are new in the Zee-Babu model can explain the large annihilation cross section of a dark matter pair into two photons as hinted by the recent analysis of the Fermi gamma-ray space telescope data. These new scalars can also enhance the B(H ->gamma gamma), as the recent LHC results may suggest. The dark matter relic density can be explained. The direct detection rate of the dark matter is predicted to be about one order of magnitude down from the current experimental bound in the first scenario.

  
  

  

• Invisible Higgs decay width versus dark matter direct detection cross section in Higgs portal dark matter models

  Title	: Invisible Higgs decay width versus dark matter direct detection cross section in Higgs portal dark matter models
  Journal	: PHYSICAL REVIEW D, 2014

  
  

  논문

  NUMBER	P14034
  AUTHOR	Ko, P.,Baek, Seungwon,Park, Wan-Il
  TITLE	Invisible Higgs decay width versus dark matter direct detection cross section in Higgs portal dark matter models
  ARCHIVE	1405.3530
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2014
  ABSTRACT	The correlation between the invisible Higgs branching ratio (B-h(inv)) versus dark matter (DM) direct detection cross section (sigma(SI)(p)) in Higgs portal singlet fermion DM (SFDM) or vector DM (VDM) models is usually presented in the effective field theory (EFT) framework. In this paper, we derive the explicit expressions for this correlation within UV completions of SFDM and VDM models with Higgs portals, and we discuss the limitations of the EFT approach. We show that there are at least two additional hidden parameters in sigma(SI)(p) in the UV completions: the singletlike scalar mass m(2) and its mixing angle alpha with the SM Higgs boson (h). In particular, if the singletlike scalar is lighter than the SM Higgs boson (m(2) < m(h) cos alpha/root 1+cos(2)alpha) the collider bound becomes weaker than the one based on EFT.

  
  

  

• Higgs portal vector dark matter for GeV scale gamma-ray excess from galactic center

  Title	: Higgs portal vector dark matter for GeV scale gamma-ray excess from galactic center
  Journal	: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2014

  
  

  논문

  NUMBER	P14029
  AUTHOR	Ko, P.,Park, Wam-Il,Tang, Yong
  TITLE	Higgs portal vector dark matter for GeV scale gamma-ray excess from galactic center
  ARCHIVE	1404.5257
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2014
  ABSTRACT	We show that the GeV scale -y-ray excess from the direction of the Galactic Center can be naturally explained by the pair annihilation of Abelian vector dark matter (VDM) into a pair of dark Higgs bosons (VV -> phi phi), followed by the subsequent decay of phi into b (b) over bar or tau(tau) over bar. All the processes are described by a renormalizable VDM model with the Higgs portal, which is naturally flavor-dependent. Some parameter space of this scenario can be tested at the near future direct dark matter search experiments such as LUX and XENON1T.

  
  

  

• Renormalization group-induced phenomena of top pairs from four-quark effective operators

  Title	: Renormalization group-induced phenomena of top pairs from four-quark effective operators
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2014

  
  

  논문

  NUMBER
  AUTHOR	Jung, Sunghoon,Yu, Chaehyun,Yoon, Yeo Woong,Ko, P.
  TITLE	Renormalization group-induced phenomena of top pairs from four-quark effective operators
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2014
  ABSTRACT	We study the renormalization group(RG) evolution of four-quark operators that contribute to the top pair production. In particular, we focus on the cases in which certain observables are first induced from the one-loop RG while being absent at tree-level. From the operator mixing pattern, we classify all such RG-induced phenomena and underlying models that can induce them. We then calculate the full one-loop QCD RG evolution as the leading estimator of the effects and address the question of which RG-induced phenomena have largest and observable effects. The answer is related to the color structure of QCD. The studied topics include the RG-induction of top asymmetries, polarizations and polarization mixings as well as issues arising at this order. The RG-induction of top asymmetries is further compared with the generation of asymmetries from QCD and QED at one-loop order. We finally discuss the validity of using the RG as the proxy of one-loop effects on the top pair production. As an aside, we clarify the often-studied relations between top pair observables.

  
  

  

• Correlation of top asymmetries: Loop versus tree origins

  Title	: Correlation of top asymmetries: Loop versus tree origins
  Journal	: PHYSICAL REVIEW D, 2014

  
  

  논문

  NUMBER	P14028
  AUTHOR	Jung, Sunghoon,Yu, Chaehyun,Yoon, Yeo Woong,Ko, P.
  TITLE	Correlation of top asymmetries: Loop versus tree origins
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2014
  ABSTRACT	We study the correlation of top asymmetries that are sensitive to the different origin of (a new contribution to) the total asymmetry: loop- or tree-level origins. We find that both the size and the sign of the correlation between total and t (t) over barj inclusive asymmetries are inherently different depending on the origin. We demonstrate the correlation by using the color-singlet Z and the pure axigluon taken as representative models of loop- and tree-induced total asymmetries. We calculate the next-to-leading order QCD corrections to the Z and perform Monte Carlo event generation. The correlation is understood in the QCD eikonal approximation using its color structure.

  
  

  

• Indirect and direct signatures of Higgs portal decaying vector dark matter for positron excess in cosmic rays

  Title	: Indirect and direct signatures of Higgs portal decaying vector dark matter for positron excess in cosmic rays
  Journal	: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2014

  
  

  논문

  NUMBER	P14009
  AUTHOR	Ko, P.,Baek, Seungwon,Park, Wan-Il,Tang, Yong
  TITLE	Indirect and direct signatures of Higgs portal decaying vector dark matter for positron excess in cosmic rays
  ARCHIVE	1402.2115
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2014
  ABSTRACT	We investigate the indirect signatures of the Higgs portal U(1)x vector dark matter (VDM) X mu from both its pair annihilation and decay. The VDM is stable at renormalizable level by Z(2) symmetry, and thermalized by Higgs-portal interactions. It can also decay by some nonrenormalizable operators with very long lifetime at cosmological time scale. If dim-6 operators for VDM decays are suppressed by 10(16) GeV scale, the lifetime of VDM with mass similar to 2 TeV is just right for explaining the positron excess in cosmic ray observed by PAMELA and AMS02 Collaborations. The VDM decaying into mu(+)mu(-) can fit the data, evading various constraints on cosmic rays. We give one UV-complete model as an example. This scenario for Higgs portal decaying VDM with mass around similar to 2 TeV can be tested by DM direct search at XENON1T, and also at the future colliders by measuring the Higgs self-couplings.

  
  

  

• Higgs-dilaton(radion) system confronting the LHC Higgs data

  Title	: Higgs-dilaton(radion) system confronting the LHC Higgs data
  Journal	: PHYSICS LETTERS B, 2014

  
  

  논문

  NUMBER
  AUTHOR	Jung, Dong-Won,Ko, P.
  TITLE	Higgs-dilaton(radion) system confronting the LHC Higgs data
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, 2014
  ABSTRACT	We consider the Higgs-dilaton(radion) system using the trace of energy-momentum tensor (Thi,) with the full Standard Model (SM) gauge symmetry G(SM) SU(3)(c) x SU(2)(L) x U(1)(Y), and find out that the resulting phenomenology for the Higgs-dilaton(radion) system is distinctly different from the earlier studies based on the T-mu mu with the unbroken subgroup H-sm equivalent to SU(3)(c), x U(1)(em) of G(SM). After electroweak symmetry breaking (EWSB), the SM Higgs boson and dilaton(radion) will mix with each other, and there appear two Higgs-like scalar bosons and the Higgs-dilaton mixing changes the scalar phenomenology in interesting ways. The signal strengths for the gg-initiated channels could be modified significantly compared with the SM predictions due to the QCD scale anomaly and the Higgs-dilaton(radion) mixing, whereas anomaly contributions are almost negligible for other channels. We also discuss the selfcouplings and the signal strengths of the 126 GeV scalar boson in various channels and possible constraints from the extra light/heavy scalar boson. The Higgs-dilaton(radion) system considered in this work has a number of distinctive features that could be tested by the upcoming LHC running and at the ILC. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.orsilicenses/4/3M).

  
  

  

• Self-interacting scalar dark matter with local Z(3) symmetry

  Title	: Self-interacting scalar dark matter with local Z(3) symmetry
  Journal	: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2014

  
  

  논문

  NUMBER	P14010
  AUTHOR	Ko, P.,Tang, Yong
  TITLE	Self-interacting scalar dark matter with local Z(3) symmetry
  ARCHIVE	1402.6449
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2014
  ABSTRACT	We construct a self-interacting scalar dark matter (DM) model with local discrete Z(3) symmetry that stabilizes a weak scale scalar dark matter X. The model assumes a hidden sector with a local U(1)x dark gauge symmetry, which is broken spontaneously into Z(3) subgroup by nonzero VEV of dark Higgs field phi(X) ( not equal 0). Compared with global Z(3) DM models, the local Z(3) model has two new extra fields: a dark gauge field Z and a dark Higgs field (phi) (a remnant of the U(1)(X) breaking). After imposing various constraints including the upper bounds on the spin-independent direct detection cross section and thermal relic density, we find that the scalar DM with mass less than 125 GeV is allowed in the local Z(3) model, in contrary to the global Z(3) model. This is due to new channels in the DM pair annihilations open into Z and phi in the local Z(3) model. Most parts of the newly open DM mass region can be probed by XENON1T and other similar future experiments. Also if phi is light enough (a few MeV less than or similar to m(phi) less than or similar to O(100) MeV), it can generate a right size of DM self-interaction and explain the astrophysical small scale structure anomalies. This would lead to exotic decays of Higgs boson into a pair of dark Higgs bosons, which could be tested at LHC and ILC.

  
  

  

• Higgs phenomenology in Type-I 2HDM with U(1)(H) Higgs gauge symmetry

  Title	: Higgs phenomenology in Type-I 2HDM with U(1)(H) Higgs gauge symmetry
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2014

  
  

  논문

  NUMBER	P13055
  AUTHOR	Ko, P.,Yu, Chaehyun,Omura, Yuji
  TITLE	Higgs phenomenology in Type-I 2HDM with U(1)(H) Higgs gauge symmetry
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2014
  ABSTRACT	It is well known that generic two-Higgs-doublet models (2HDMs) suffer from potentially large Higgs-mediated flavor-changing neutral current (FCNC) problem, unless additional symmetries are imposed on the Higgs fields thereby respecting the Natural Flavor Conservation Criterion (NFC) by Glashow and Weinberg. A common way to respect the NFC is to impose Z(2) symmetry which is softly broken by a dim-2 operator. Another new way is to introduce local U(1)(H) Higgs flavor symmetry that distinguishes one Higgs doublet from the other. In this paper, we consider the Higgs phenomenology in Type-I 2HDMs with the U(1)(H) symmetry with the simplest U(1)(H) assignments that the SM fermions are all neutral under U(1)(H), and we make detailed comparison with the ordinary Type-I 2HDM. After imposing various constraints such as vacuum stability and perturbativity as well as the electroweak precision observables and collider search bounds on charged Higgs boson, we find that the allowed Higgs signal strengths in our model are much broader than those in the ordinary Type-I 2HDM, because of newly introduced U(1)(H)-charged singlet scalar and U(1)(H) gauge boson. Still the ATLAS data on gg -> h -> gamma gamma cannot be accommodated. Our model could be distinguished from the ordinary 2HDM with the Z(2) symmetry in a certain parameter region and some channels. If the couplings of the new boson turn out to be close to those in the SM, it would be essential to search for extra U(1)(H) gauge boson and/or one more neutral scalar boson to distinguish two models.

  
  

  

• Implications of LHC data on 125 GeV Higgs-like boson for the Standard Model and its various extensions

  Title	: Implications of LHC data on 125 GeV Higgs-like boson for the Standard Model and its various extensions
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2013

  
  

  논문

  NUMBER	P13023
  AUTHOR	Jung, Sunghoon,Ko, P.
  TITLE	Implications of LHC data on 125 GeV Higgs-like boson for the Standard Model and its various extensions
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2013
  ABSTRACT	Recent data on 125 GeV Higgs-like boson at the LHC start to constrain the electroweak symmetry breaking (EWSB) sector of the Standard Model (SM) and its various extensions. If one imposes the local gauge symmetry of the SM (SU(3)(c) x SU(2)(L) x U(1)(Y)) to any possible new physics scenarios, the SM Higgs properties will be modified by intrinsically two ways: by new physics either coupling directly to the SM Higgs boson h, or affecting indirectly the SM Higgs properties through the mixing of h with a SM singlet scalar s. (Here s is a singlet under the SM gauge group, but may be charged under a new gauge charge and can have nonrenormalizable couplings to non-SM particles.) The models of two Higgs doublets, extra sequential and mirror fermions belong to the first category, whereas the models with a hidden sector dark matter, extra vector-like fermions and new charged vector bosons, which can enhance the diphoton rate of the SM Higgs-like resonance, belong to the second category. We perform a global fit to data in terms of the effective Lagrangian description of two interaction eigenstates of scalar bosons, a SM Higgs and a singlet scalar, and their mixing. This framework is more suitable to study singlet-extended scenarios discussed above compared to other approaches based on the Lagrangian of mass eigenstates. With fairly model-independent assumptions, the effective Lagrangian contains at most four free parameters still encompassing the majority of models in the literature. Interestingly, the SM gives the best fit if all data from ATLAS and CMS are used, whereas various singlet extensions can fit better to individual ATLAS or CMS data. Without further assumptions, an upper bound on the total width (or, non-standard branching ratio) is generically obtained. Furthermore, the global fit based on our parameterization can be used to probe interactions of the singlet scalar if the singlet resides below 2m(W).

  
  

  

• Singlet portal extensions of the standard seesaw models to a dark sector with local dark symmetry

  Title	: Singlet portal extensions of the standard seesaw models to a dark sector with local dark symmetry
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2013

  
  

  논문

  NUMBER	P13057
  AUTHOR	Ko, P.,Baek, Seungwon,Park, Wan-Il
  TITLE	Singlet portal extensions of the standard seesaw models to a dark sector with local dark symmetry
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2013
  ABSTRACT	Assuming (i) the seesaw mechanism works for neutrino masses and mixings, (i i) dark matter is absolutely stable due to unbroken U(1)(X) dark gauge symmetry, and (i i i) the singlet fields ((HH)-H-dagger and N-R) are portal to the dark sector, we construct a simple model which is consistent with all the cosmological observations as well as terrestrial experiments available as of now, including leptogenesis, extra dark radiation of similar to 8% (resulting in N-eff = 3.130 the effective number of neutrino species), Higgs inflation, small and large scale structure formation, and current relic density of scalar dark matter (X). The electroweak vacuum of this model is stable up to Planck scale for m(H) = 125GeV without any other new physics. The Higgs signal strength is equal to one as in the standard model for unbroken U(1)(X) case with a scalar dark matter, but it could be less than one independent of decay channels if the dark matter is a dark sector fermion or if U(1)(X) is spontaneously broken, because of a mixing with a new neutral scalar boson in the models. Detailed study of Higgs properties at the LHC would shed light on the models described in this work.

  
  

  

• Higgs portal vector dark matter: revisited

  Title	: Higgs portal vector dark matter: revisited
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2013

  
  

  논문

  NUMBER	P12082
  AUTHOR	Ko, P.,Baek, Seungwon,Senaha, Eibun,Park, Wan-Il
  TITLE	Higgs portal vector dark matter: revisited
  ARCHIVE	1212.2131
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2013
  ABSTRACT	We revisit the Higgs portal vector dark matter model including a hidden sector Higgs field that generates the mass of the vector dark matter. The model becomes renormalizable and has two scalar bosons, the mixtures of the standard model (SM) Higgs and the hidden sector Higgs bosons. The strong bound from direct detection such as XENON100 is evaded due to the cancellation mechanism between the contributions from two scalar bosons. As a result, the model becomes still viable in large range of dark matter mass, contrary to some claims in the literature. The Higgs properties are also affected, the signal strengths for the Higgs boson search being universally suppressed relative to the SM value, which could be tested at the LHC in the future.

  
  

  

• B -> D-(*())tau nu and B -> tau nu in chiral U(1) models with flavored multi Higgs doublets

  Title	: B -> D-(*())tau nu and B -> tau nu in chiral U(1) models with flavored multi Higgs doublets
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2013

  
  

  논문

  NUMBER	P12084
  AUTHOR	Ko, P.,Yu, Chaehyun
  TITLE	B -> D-(*())tau nu and B -> tau nu in chiral U(1) models with flavored multi Higgs doublets
  ARCHIVE	1212.4607 [hep-ph]
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2013
  ABSTRACT	We discuss semileptonic and leptonic B decays, B -> D-(*())tau nu and B -> tau nu, in the chiral U(1) models which were proposed by the present authors in the context of the top forward-backward asymmetry (A(FB)(t)) observed at the Tevatron. In these models, extra Higgs doublets with nonzero U(1) charges are required in order to make the realistic mass matrix for up-type quarks. Then the extra (pseudo)scalars contribute to A(FB)(t) with large flavor-changing Yukawa couplings involving top quark. The contribution of the charged Higgs to A(FB)(t) is negligible, but it may significantly affect B decays: especially, B -> D-(*())tau nu and B -> tau nu. We investigate constraints on the B decays, based on the recent results in BaBar and Belle experiments, and discuss the possibility that the allowed parameter region in the B decays can achieve large A(FB)(t).

  
  

  

• Top A(FB) at the Tevatron vs. charge asymmetry at the LHC in chiral U(1) flavor models with flavored Higgs doublets

  Title	: Top A(FB) at the Tevatron vs. charge asymmetry at the LHC in chiral U(1) flavor models with flavored Higgs doublets
  Journal	: EUROPEAN PHYSICAL JOURNAL C, 2013

  
  

  논문

  NUMBER	P12024
  AUTHOR	Ko, P.,Yu, Chaehyun,Omura, Yuji
  TITLE	Top A(FB) at the Tevatron vs. charge asymmetry at the LHC in chiral U(1) flavor models with flavored Higgs doublets
  ARCHIVE	1205.0407
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL C, 2013
  ABSTRACT	We consider the top forward-backward (FB) asymmetry at the Tevatron and top charge asymmetry at the LHC within chiral U(1) models with flavor-dependent U(1) charges and flavored Higgs fields, which were introduced in Ko et al. (J. High Energy Phys. 1201:147, 2012). In this model, one has to include the flavor-changing couplings of the Higgs bosons as well as the Z to the up-type quarks. The models could enhance not only the top forward-backward asymmetry at the Tevatron, but also the top charge asymmetry at LHC, without too large same-sign top-quark pair production rates. Also the m(t (t) over bar) distribution at high m(t (t) over bar) shows less deviations from the SM predictions. We identify parameter spaces for the U(1) gauge boson and (pseudo) scalar Higgs bosons where all the experimental data could be accommodated, including the case with about 125 GeV Higgs boson, as suggested recently by ATLAS and CMS.

  
  

  

• Vacuum structure and stability of a singlet fermion dark matter model with a singlet scalar messenger

  Title	: Vacuum structure and stability of a singlet fermion dark matter model with a singlet scalar messenger
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2012

  
  

  논문

  NUMBER	P12061
  AUTHOR	Ko, P.,Baek, Seungwon,Senaha, Eibun,Park, Wan-Il
  TITLE	Vacuum structure and stability of a singlet fermion dark matter model with a singlet scalar messenger
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2012
  ABSTRACT	We consider the issue of vacuum stability and triviality bound of the singlet extension of the Standard Model (SM) with a singlet fermion dark matter (DM). In this model, the singlet scalar plays the role of a messenger between the SM sector and the dark matter sector. This model has two Higgs-like scalar bosons, and is consistent with all the data on electroweak precision tests, thermal relic density of DM and its direct detection constraints. We show that this model is stable without hitting Landau pole up to Planck scale for 125GeV Higgs boson. We also perform a comprehensive study of vacuum structure, and point out that a region where electroweak vacuum is the global minimum is highly limited. In this model, both Higgs-like scalar bosons have reduced couplings to the SM weak gauge bosons and the SM fermions, because of the mixing between the SM Higgs boson and the singlet scalar. There is also a possibility of their invisible decay(s) into a pair of DMs. Therefore this model would be disfavored if the future data on the (sigma . B)(VV) or (sigma . B)(f (f) over bar) with V = gamma, W, Z and f = b, tau turn out larger than the SM predictions.

  
  

  

• A resolution of the flavor problem of two Higgs doublet models with an extra U(1)(H) symmetry for Higgs flavor

  Title	: A resolution of the flavor problem of two Higgs doublet models with an extra U(1)(H) symmetry for Higgs flavor
  Journal	: PHYSICS LETTERS B, 2012

  
  

  논문

  NUMBER	P11063
  AUTHOR	Ko, P.,Yu, Chaehyun,Omura, Yuji
  TITLE	A resolution of the flavor problem of two Higgs doublet models with an extra U(1)(H) symmetry for Higgs flavor
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, 2012
  ABSTRACT	We propose to implement the Natural Flavor Conservation criterion in the two Higgs doublet model (2HDM) to an extra U(1)(H) gauge symmetry for Higgs flavor, assuming two Higgs doublets carry different U(1)(H) charges. Then one can easily avoid the tree-level FCNC from neutral Higgs mediations using local gauge symmetries, instead of softly broken ad hoc Z(2) symmetry, and the pseudoscalar boson could be eaten by extra Z(H) boson. Imposing the anomaly cancellation, we find that the U(1)(H) in the Type-II and Type-IV 2HDMs become leptophobic and leptophilic, respectively. For the Type-I case, U(1)(H) depends on two parameters, and some simple cases include U(1)(H) = U(1)(B-L), U(1)(R), or U(1)(Y). We sketch qualitative phenomenology of these models. (C) 2012 Elsevier B.V. All rights reserved.

  
  

  

• Simplified models for LHC new physics searches

  Title	: Simplified models for LHC new physics searches
  Journal	: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 2012

  
  

  논문

  NUMBER	P11024
  AUTHOR	Ko, Pyungwon
  TITLE	Simplified models for LHC new physics searches
  ARCHIVE	arXiv:1105.2838
  FILE
  JOURNAL	JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 2012
  ABSTRACT	This document proposes a collection of simplified models relevant to the design of new-physics searches at the Large Hadron Collider (LHC) and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the Topologies for Early LHC Searches workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first similar to 50-500 pb(-1) of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  
  

  

• Top forward-backward asymmetry and the CDF Wjj excess in leptophobic U(1) flavor models

  Title	: Top forward-backward asymmetry and the CDF Wjj excess in leptophobic U(1) flavor models
  Journal	: PHYSICAL REVIEW D, 2012

  
  

  논문

  NUMBER	P11042
  AUTHOR	Ko, P.,Yu, Chaehyun,Omura, Yuji
  TITLE	Top forward-backward asymmetry and the CDF Wjj excess in leptophobic U(1) flavor models
  ARCHIVE	arXiv:1108.0350
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2012
  ABSTRACT	We construct anomaly-free leptophobic U(1) flavor models with light Z (similar to 145 GeV). In order to allow renormalizable Yukawa interactions for the standard model chiral fermions, new Higgs doublets with nonzero U(1) charges are introduced. Then the neutral (pseudo) scalar Higgs bosons as well as Z contribute to the t (t) over bar and the same sign top pair productions [sigma(t (t) over bar) and sigma(tt)], and one can evade the strong constraint from sigma(tt). The top forward-backward asymmetry (A(FB)) and Wjj excess at CDF could be accommodated by A(FB)(New) = 0.084 similar to 0.12 and sigma(Wjj) less than or similar to O(10) pb X sin(2)2 beta.

  
  

  

• Dijet resonance from leptophobic Z and light baryonic cold dark matter

  Title	: Dijet resonance from leptophobic Z and light baryonic cold dark matter
  Journal	: PHYSICS LETTERS B, 2012

  
  

  논문

  NUMBER	P11016
  AUTHOR	Ko, P.,Yu, Chaehyun,Omura, Yuji
  TITLE	Dijet resonance from leptophobic Z and light baryonic cold dark matter
  ARCHIVE	1104.4066
  FILE
  JOURNAL	PHYSICS LETTERS B, 2012
  ABSTRACT	In light of the recent CDF report on the excess in the Wjj channel, we analyze (non)supersymmetric U(1)(B) x U(1)(l) model, interpreting the dijet peak as a leptophobic U(1)(B) gauge boson. If this excess is confirmed, it has an interesting implication for the baryonic cold dark matter (CDM) in the model: there should be light CDM with a few GeV mass, and direct detection cross section at the level of a few x 10(-2) pb. (C) 2012 Elsevier B.V. All rights reserved.

  
  

  

• Light dark matter in leptophobic Z models

  Title	: Light dark matter in leptophobic Z models
  Journal	: PHYSICAL REVIEW D, 2012

  
  

  논문

  NUMBER	P11025
  AUTHOR	Ko, P.,Omura, Y.
  TITLE	Light dark matter in leptophobic Z models
  ARCHIVE	arXiv:1106.0885
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2012
  ABSTRACT	Recent experimental results in direct dark matter detection may be interpreted in terms of a dark matter particle of mass around 10 GeV/c(2). We show that the required scenario can be realized with a new dark matter particle charged under an extra Abelian gauge boson Z that couples to quarks but not leptons. This is possible provided the Z gauge boson is very light, around 10-20 GeV/c(2) in mass, and the gauge coupling constant is small, alpha similar to 10(-5). Such scenarios are not constrained by accelerator data.

  
  

  

• Mass dependent top forward-backward asymmetry in the effective Lagrangian approach: Addendum to Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron

  Title	: Mass dependent top forward-backward asymmetry in the effective Lagrangian approach: Addendum to Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron
  Journal	: PHYSICS LETTERS B, 2012

  
  

  논문

  NUMBER	P11043
  AUTHOR	Ko, P.
  TITLE	Mass dependent top forward-backward asymmetry in the effective Lagrangian approach: Addendum to Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron
  ARCHIVE	1111.3180 [hep-ph]
  FILE
  JOURNAL	PHYSICS LETTERS B, 2012
  ABSTRACT	Recently the CDF and the D0 Collaborations presented the data on the top forward-backward (FB) asymmetry A(FB) as functions of M-t((t)) over bar and Delta y equivalent to y(t) - y ((t)) over bar. We study these observables in the effective Lagrangian approach with dimension-6 qqtt contact interactions, and compare with the CDF and DO data. When we stay within the validity region of the effective Lagrangian approach, the mass dependent top FB asymmetry turns out to be smaller than the CDF data, more than 2-sigma away. If this discrepancy remains in the future data with better statistics, it would imply that the effective Lagrangian approach is not adequate for the top FB asymmetry, and a new physics scale around a few hundred GeV in the t- or u-channel may be responsible for the observed top FB asymmetry. (C) 2012 Elsevier B.V. All rights reserved.

  
  

  

• Search for the Higgs portal to a singlet fermionic dark matter at the LHC

  Title	: Search for the Higgs portal to a singlet fermionic dark matter at the LHC
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2012

  
  

  논문

  NUMBER	P11064
  AUTHOR	Ko, P.,Baek, Seungwon,Park, Wan-Il
  TITLE	Search for the Higgs portal to a singlet fermionic dark matter at the LHC
  ARCHIVE	arXiv:1112.1847
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2012
  ABSTRACT	We consider a simple extension of the standard model with a singlet fermionic dark matter. Its thermal relic density can be easily accommodated by a real Singlet scalar messenger that mixes with the standard model Higgs boson. The model can change significantly the Higgs signals at the LTIC via sizable invisible decays of two Higgs-like scalar bosons. After imposing the constraints from the electroweak precision tests, colliders and dark matter search experiments, one concludes that two or one or none of the two Higgs bosons, depending on the mass relations among two scalar bosons and the dark matter fermion and their couplings. In particular, if a standard model Higgs-like scalar boson is discovered around 120-125 GeV region at the LHC, it would be almost impossible to find the second Higgs-like boson since it is mostly a singlet scalar, whether it is heavier or lighter. This model can be further tested by direct dark matter search experiments.

  
  

  

• Chiral U(1) flavor models and flavored Higgs doublets: the top FB asymmetry and the Wjj

  Title	: Chiral U(1) flavor models and flavored Higgs doublets: the top FB asymmetry and the Wjj
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2012

  
  

  논문

  NUMBER	P11045
  AUTHOR	Ko, P.,Yu, Chaehyun,Omura, Yuji
  TITLE	Chiral U(1) flavor models and flavored Higgs doublets: the top FB asymmetry and the Wjj
  ARCHIVE	1008.4005
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2012
  ABSTRACT	We present U(1) flavor models for leptophobic Z with flavor dependent couplings to the right-handed up-type quarks in the Standard Model (SM), which can accommodate the recent data on the top forward-backward (FB) asymmetry and the dijet resonance associated with a W boson reported by CDF Collaboration. Such flavor-dependent leptophobic charge assignments generally require extra chiral fermions for anomaly cancellation. Also the chiral nature of U(1) flavor symmetry calls for new U(1)-charged Higgs doublets in order for the SM fermions to have realistic renormalizable Yukawa couplings. The stringent constraints from the top FB asymmetry at the Tevatron and the same sign top pair production at the LHC can be evaded due to contributions of the extra Higgs doublets. We also show that the extension could realize cold dark matter candidates.

  
  

  

• Possible common origin of the top forward-backward asymmetry and the CDF Wjj excess

  Title	: Possible common origin of the top forward-backward asymmetry and the CDF Wjj excess
  Journal	: PHYSICAL REVIEW D, 2011

  
  

  논문

  NUMBER	P11017
  AUTHOR	Ko, P.
  TITLE	Possible common origin of the top forward-backward asymmetry and the CDF Wjj excess
  ARCHIVE	arXiv:1104.4443
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2011
  ABSTRACT	A color-singlet neutral vector boson is considered as a possible common origin of the top forward-backward asymmetry and the CDF dijet resonance. We identify chiral and flavor structures of the couplings of this new vector boson to the standard model quarks for which one could accommodate both data. We also demonstrate that nonvanishing observables involving longitudinal top polarizations can provide useful criteria for the possible existence of parity violating new physics in the q (q) over bar -> t (t) over bar process, and discrimination between the flavor-conserving and flavor-violating cases.

  
  

  

• Supersymmetric U(1)(B) x U(1)(L) model with leptophilic and leptophobic cold dark matters

  Title	: Supersymmetric U(1)(B) x U(1)(L) model with leptophilic and leptophobic cold dark matters
  Journal	: PHYSICS LETTERS B, 2011

  
  

  논문

  NUMBER	P10043
  AUTHOR	Ko, P.,Omura, Y.
  TITLE	Supersymmetric U(1)(B) x U(1)(L) model with leptophilic and leptophobic cold dark matters
  ARCHIVE	1012.4679
  FILE
  JOURNAL	PHYSICS LETTERS B, 2011
  ABSTRACT	We consider a supersymmetric model with extra U(1)(B) x U(1)(L) gauge symmetry that is broken spontaneously. Salient features of this model are that there are three different types of cold dark matter (CDM) candidates, and neutral scalar sector has a rich structure. Light CDM with sigma(Sl) similar to 10(-3+/-1) pb can be easily accommodated by leptophobic dark matter (chi(B)) with correct relic density, if the U(1)(B) gauge boson mass is around 2m(chi B). Also the PAMELA and Fermi/EAT data can be fit by leptophilic CDM with mass similar to 1 TeV. There could be interesting signatures of new fermions and new gauge bosons at the LHC. (C) 2011 Elsevier B.V. All rights reserved.

  
  

  

• Longitudinal top polarization as a probe of a possible origin of forward-backward asymmetry of the top quark at the Tevatron

  Title	: Longitudinal top polarization as a probe of a possible origin of forward-backward asymmetry of the top quark at the Tevatron
  Journal	: PHYSICS LETTERS B, 2011

  
  

  논문

  NUMBER	P10038
  AUTHOR	Ko, P.
  TITLE	Longitudinal top polarization as a probe of a possible origin of forward-backward asymmetry of the top quark at the Tevatron
  ARCHIVE	1011.5976
  FILE
  JOURNAL	PHYSICS LETTERS B, 2011
  ABSTRACT	If the forward-backward (FB) asymmetry of top quark (A(FB)) observed at the Tevatron deviates from the SM prediction, there must be P-violating interactions in q (q) over bar -> t (t) over bar. This new interaction will necessarily affect the top spin polarization. In this Letter, we perform a model independent analysis on the longitudinal (anti)top polarization (P-L and (P) over bar (L)) using an effective lagrangian with dim-6 four-quark operators relevant for q (q) over bar -> t (t) over bar, and show that the P-odd observable corresponding to the polarization difference (P-L - (P) over bar (L)) gives important informations on the chiral structures of new physics that might be relevant to the A(FB). (C) 2011 Elsevier B.V. All rights reserved.

  
  

  

• Scale Invariant Extension of the Standard Model with a Strongly Interacting Hidden Sector

  Title	: Scale Invariant Extension of the Standard Model with a Strongly Interacting Hidden Sector
  Journal	: PHYSICAL REVIEW LETTERS, 2011

  
  

  논문

  NUMBER	P11010
  AUTHOR	Ko, P.
  TITLE	Scale Invariant Extension of the Standard Model with a Strongly Interacting Hidden Sector
  ARCHIVE	arXiv:1103.2571
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2011
  ABSTRACT	We present a scale invariant extension of the standard model with a new QCD-like strong interaction in the hidden sector. A scale Lambda(H) is dynamically generated in the hidden sector by dimensional transmutation, and chiral symmetry breaking occurs in the hidden sector. This scale is transmitted to the SM sector by a real singlet scalar messenger S and can trigger electroweak symmetry breaking. Thus all the mass scales in this model arise from the hidden sector scale Lambda(H), which has quantum mechanical origin. Furthermore, the lightest hadrons in the hidden sector are stable by the flavor conservation of the hidden sector strong interaction, and could be the cold dark matter (CDM). We study collider phenomenology, relic density, and direct detection rates of the CDM of this model.

  
  

  

• pp -> J/psi plus Gamma plus X as a clean probe to the quarkonium production mechanism

  Title	: pp -> J/psi plus Gamma plus X as a clean probe to the quarkonium production mechanism
  Journal	: PHYSICAL REVIEW D, 2011

  
  

  논문

  NUMBER	P10017
  AUTHOR	Ko, P.,Yu, Chaehyun
  TITLE	pp -> J/psi plus Gamma plus X as a clean probe to the quarkonium production mechanism
  ARCHIVE	1006.3846
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2011
  ABSTRACT	We report that, unlike most inclusive quarkonium-production processes, the production rate for pp -> J/psi + Gamma + X dominantly depends on two not well-known long-distance nonrelativistic QCD matrix elements, < O-8(J/psi)(S-3(1))> and < O-8(Gamma)(S-3(1))> at leading order in the strong coupling constant, which account for the transition probabilities of the color-octet spin-triplet heavy-quark-antiquark pairs c (c) over bar (8)(S-3(1)) -> J/psi and b (b) over bar (8)(S-3(1)) -> Gamma, respectively. With the integrated luminosity similar to 100 fb(-1) at the center-of-momentum energy root s = 14 TeV we expect that approximately 1900 pp -> J/psi + Gamma + X events can be observed at the CERN Large Hadron Collider by tagging muon pairs, which are enough to probe to the color-octet mechanism. The forthcoming measurement may provide a useful constraint to resolve the decade-old puzzle for the polarization of prompt J/psi at the Fermilab Tevatron. If corresponding measured rate is significantly less than the prediction, it may imply that the current values for the color-octet matrix elements are overestimated.

  
  

  

• Electroweak symmetry breaking and cold dark matter from strongly interacting hidden sector

  Title	: Electroweak symmetry breaking and cold dark matter from strongly interacting hidden sector
  Journal	: PHYSICS LETTERS B, 2011

  
  

  논문

  NUMBER	P07050
  AUTHOR	Ko, P.
  TITLE	Electroweak symmetry breaking and cold dark matter from strongly interacting hidden sector
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, 2011
  ABSTRACT	We consider a hidden sector with a vectorlike confining gauge theory like QCD with N(h,c) colors and N(h,f) light quarks Q(h) in the hidden sector. Then a scale Lambda(H) would be generated by dimensional transmutation, and chiral symmetry breaking occurs in the hidden sector. This scale Lambda(H) can play a role of the SM Higgs mass parameter, triggering electroweak symmetry breaking (EWSB). Furthermore the lightest mesons in the hidden sector is stable by flavor conservation of the hidden sector strong interaction, and could be a good cold dark matter (CDM). We study collider phenomenology, and relic density and direct detection rates of the CDM of this model. (C) 2010 Elsevier B.V. All rights reserved.

  
  

  

• Inclusive double-quarkonium production at the Large Hadron Collider

  Title	: Inclusive double-quarkonium production at the Large Hadron Collider
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2011

  
  

  논문

  NUMBER	P10023
  AUTHOR	Ko, P.,Yu, Chaehyun
  TITLE	Inclusive double-quarkonium production at the Large Hadron Collider
  ARCHIVE	1007.3095
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2011
  ABSTRACT	Based on the nonrelativistic QCD (NRQCD) factorization formalism, we investigate inclusive productions of two spin-triplet S-wave quarkonia pp -> 2J/psi + X, 2 gamma + X, and J/psi + gamma + X at the CERN Large Hadron Collider. The total production rates integrated over the rapidity (y) and transverse-momentum (pT) ranges vertical bar y vertical bar < 2.4 and pT < 50GeV are predicted to be sigma[pp -> 2J/psi + X] = 22 (35) nb, sigma[pp -> 2 gamma + X] = 24 (49) pb, and sigma[pp -> J/psi + gamma + X] = 7 (13) pb at the center-of-momentum energy root s = 7 (14) TeV. In order to provide predictions that can be useful in both small- and large-pT regions, we do not employ the fragmentation approximation and we include the spin-triplet S-wave color-singlet and color-octet channels for each quarkonium final state at leading order in the strong coupling. The pT distributions of pp -> 2J/psi + X and 2 gamma + X in the low-pT region are dominated by the color-singlet contributions. At leading order in the strong coupling, the color-singlet channel is absent for pp -> J/psi + gamma + X. Therefore, the process pp -> J/psi + gamma + X may provide a useful probe to the color-octet mechanism of NRQCD.

  
  

  

• Addendum to: Implications of the measurements of B-S-(B)over-bar(S) mixing on SUSY models

  Title	: Addendum to: Implications of the measurements of B-S-(B)over-bar(S) mixing on SUSY models
  Journal	: PHYSICAL REVIEW D, 2010

  
  

  논문

  NUMBER	P10021
  AUTHOR	Ko, P.
  TITLE	Addendum to: Implications of the measurements of B-S-(B)over-bar(S) mixing on SUSY models
  ARCHIVE	arXiv:1006.5821
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2010
  ABSTRACT	This is an addendum to the previous publication, [P. Ko and J.-h. Park, Phys. Rev. D 80, 035019 (2009).]. The semileptonic charge asymmetry in B-S decays is discussed in the context of the general minimal supersymmetric standard model with gluino-mediated flavor and CP violation in light of the recent measurements at the Tevatron.

  
  

  

• Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron

  Title	: Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron
  Journal	: PHYSICS LETTERS B, 2010

  
  

  논문

  NUMBER	P10020
  AUTHOR	Ko, P.
  TITLE	Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron
  ARCHIVE	arXiv:0912.1105
  FILE
  JOURNAL	PHYSICS LETTERS B, 2010
  ABSTRACT	Motivated by a possible anomaly in the forward-backward (FB) asymmetry of top quark (A(FB)) observed at the Tevatron, we perform a model independent analysis on q (q) over bar -> t (t) over bar using an effective Lagrangian with dim-6 four-quark operators. We derive necessary conditions on new physics structures and the couplings that are consistent with the t (t) over bar production cross section and AFB measured at the Tevatron, and discuss possible new physics scenarios that could generate such dim-6 operators. (C) 2010 Elsevier B.V. All rights reserved.

  
  

  

• Phenomenology of U(1)(L mu-L tau) charged dark matter at PAMELA/FERMI and colliders

  Title	: Phenomenology of U(1)(L mu-L tau) charged dark matter at PAMELA/FERMI and colliders
  Journal	: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2009

  
  

  논문

  NUMBER
  AUTHOR	Ko, Pyungwon
  TITLE	Phenomenology of U(1)(L mu-L tau) charged dark matter at PAMELA/FERMI and colliders
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2009
  ABSTRACT	Recent data on e(+)/e(-) and (p) over bar cosmic rays suggest that dark matter annihilate into the standard model (SM) particles through new leptophilic interaction. In this paper, we consider a standard model extension with the gauged U(1)(L mu-L tau) group, with a new Dirac fermion charged under this U(1) as a dark matter. We study the muon (g-2)(mu), thermal relic density of the cold dark matter, and the collider signatures of this model. Z productions at the Tevatron or the LHC could be easily order of O(1)-O(10(3))fb.

  
  

  

• Stable Higgs bosons as cold dark matter

  Title	: Stable Higgs bosons as cold dark matter
  Journal	: PHYSICS LETTERS B, 2009

  
  

  논문

  NUMBER	P09040
  AUTHOR	Ko, Pyungwon
  TITLE	Stable Higgs bosons as cold dark matter
  ARCHIVE	0908.0212
  FILE
  JOURNAL	PHYSICS LETTERS B, 2009
  ABSTRACT	In a class of the gauge-Higgs unification models the 4D neutral Higgs boson, which is a part of the extra-dimensional component of the gauge fields, becomes absolutely stable as a consequence of the gauge invariance and dynamically generated new parity, serving as a promising candidate for cold dark matter (CDM). We show that the observed relic abundance of cold dark matter is obtained in the SO(5) x U(l) model in the warped space with the Higgs mass around 70 GeV. The Higgs-nucleon scattering cross section is found to be close to the current CDMS II and XENON10 bounds in the direct detection of dark matter. (C) 2009 Elsevier B.V. All rights reserved.

  
  

  

• Implications of the measurements of Bs-(B)over-bars mixing on supersymmetric models

  Title	: Implications of the measurements of Bs-(B)over-bars mixing on supersymmetric models
  Journal	: PHYSICAL REVIEW D, 2009

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.
  TITLE	Implications of the measurements of Bs-(B)over-bars mixing on supersymmetric models
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2009
  ABSTRACT	We derive constraints on the mass insertion parameters from the recent measurements of B-s-(B) over bar (s) mixing, and discuss their implications on SUSY breaking mediation mechanisms and SUSY flavor models. Some SUSY flavor models are already excluded or disfavored by B-s-(B) over bar (s) mixing. We also discuss how to test the SM and SUSY models in the future experiments, by studying other CP violating observables related to b -> s transition, such as the time-dependent CP asymmetry in B-d -> phi K-S and the direct CP asymmetry in B -> X-s gamma.

  
  

  

• Sflavor mixing map viewed from a high scale in supersymmetric SU(5)

  Title	: Sflavor mixing map viewed from a high scale in supersymmetric SU(5)
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2008

  
  

  논문

  NUMBER	P07051
  AUTHOR	Ko, Pyungwon
  TITLE	Sflavor mixing map viewed from a high scale in supersymmetric SU(5)
  ARCHIVE	0809.2784
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2008
  ABSTRACT	We study flavor violation in a supersymmetric SU(5) grand unification scenario in a model-independent way employing mass insertions. We examine how the quark and the lepton sector observables restrict sfermion mixings. With a low soft scalar mass, a lepton flavor violating process provides a stringent constraint on the flavor structure of right-handed down-type squarks. In particular, mu -> e gamma turns out to be highly susceptible to the 1-3 and 2-3 mixings thereof, due to the radiative correction from the top Yukawa coupling to the scalar mass terms of 10. With a higher scalar mass around the optimal value, in contrast, the quark sector inputs such as B-meson mixings and hadron electric dipole moment, essentially determine the room for sfermion mixing. We also discuss the recent deviation observed in B-s mixing phase, projected sensitivity of forthcoming experiments, and ways to maintain the power of leptonic restrictions even after incorporating a solution to fix the incorrect quark-lepton mass relations.

  
  

  

• Neutral scalar Higgs bosons in the USSM at the LHC

  Title	: Neutral scalar Higgs bosons in the USSM at the LHC
  Journal	: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 2008

  
  

  논문

  NUMBER	P08012
  AUTHOR	Ko, P.
  TITLE	Neutral scalar Higgs bosons in the USSM at the LHC
  ARCHIVE	0801.2361
  FILE
  JOURNAL	JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 2008
  ABSTRACT	We study the possibility of discovering neutral scalar Higgs bosons in the U(1)-extended supersymmetric standard model (USSM) at the CERN Large Hadron Collider (LHC), by examining their productions via the exotic-quark loop in the gluon-fusion process at leading order. It is possible in some parameter region that the neutral scalar Higgs bosons may have stronger couplings with the exotic quarks than with top quarks. In this case, the exotic quarks may contribute more actively than top quarks in production of the neutral scalar Higgs bosons in the gluon-fusion process. We find that there is indeed some parameter region in the USSM that support our speculations.

  
  

  

• Electroweak symmetry breaking and cold dark matter from hidden sector technicolors

  Title	: Electroweak symmetry breaking and cold dark matter from hidden sector technicolors
  Journal	: INTERNATIONAL JOURNAL OF MODERN PHYSICS A, 2008

  
  

  논문

  NUMBER
  AUTHOR	Ko, Pyungwon
  TITLE	Electroweak symmetry breaking and cold dark matter from hidden sector technicolors
  ARCHIVE
  FILE
  JOURNAL	INTERNATIONAL JOURNAL OF MODERN PHYSICS A, 2008
  ABSTRACT	We consider models with a vectorlike confining gauge theory in the hidden sector, and demonstrate that the origin of the electroweak symmetry breaking (EWSB) is due to the dimensional transmutation in the hidden sector gauge theory, and the lightest mesons in the hidden sector could be a good cold dark matter (CDM) candidate. There would be more than one neutral Higgs-like scalar bosons, and they could decay mainly into the CDM pair, if that decay channel is kinemtically allowed.

  
  

  

• Holographic QCD beyond the leading order

  Title	: Holographic QCD beyond the leading order
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2008

  
  

  논문

  NUMBER	P08071
  AUTHOR	Kim, Youngman,Wu, Xiao-Hong,Ko, P.
  TITLE	Holographic QCD beyond the leading order
  ARCHIVE	0804.2710
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2008
  ABSTRACT	We consider a holographic QCD model for light mesons beyond the leading order in the context of 5-dim gauged linear sigma model on the interval in the AdS(5) space. We include two dimension-6 operators in addition to the canonical bulk kinetic terms, and study chiral dynamics of pi, rho, a(1) and some of their KK modes. As novel features of dim-6 operators, we get non-vanishing Br(a(1) -> pi gamma), the electromagnetic form factor and the charge radius of a charged pion, which improve the leading order results significantly and agree well with the experimental results.

  
  

  

• Probing nonstandard neutrino physics by two identical detectors with different baselines

  Title	: Probing nonstandard neutrino physics by two identical detectors with different baselines
  Journal	: PHYSICAL REVIEW D, 2008

  
  

  논문

  NUMBER	P08011
  AUTHOR	Ko, Pyungwon
  TITLE	Probing nonstandard neutrino physics by two identical detectors with different baselines
  ARCHIVE	arXiv:0712.4314
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2008
  ABSTRACT	The Kamioka-Korea two-detector system is a powerful experimental setup for resolving neutrino parameter degeneracies and probing CP violation in neutrino oscillation. In this paper, we study sensitivities of the same setup to several nonstandard neutrino physics such as quantum decoherence, tiny violation of Lorentz symmetry, and nonstandard interactions of neutrinos with matter. We show that it can achieve significant improvement on the current bounds on nonstandard neutrino physics. In most cases, the Kamioka-Korea two-detector setup is more sensitive than the one-detector setup, either in Kamioka or in Korea, except for the cases when Lorentz symmetry is broken in a CPT-violating manner and the nonstandard neutrino interactions with matter is present.

  
  

  

• MSSM Higgs sector CP violation at photon colliders: revisited

  Title	: MSSM Higgs sector CP violation at photon colliders: revisited
  Journal	: EUROPEAN PHYSICAL JOURNAL C, 2008

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.
  TITLE	MSSM Higgs sector CP violation at photon colliders: revisited
  ARCHIVE
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL C, 2008
  ABSTRACT	The CP violating phases in soft SUSY breaking terms may induce indirect CP violation in the neutral Higgs boson sector through SUSY particle loops as well as direct CP violation in the gamma gamma -> H-i (i=1,2,3) through CP violating vertices. We present a complete analysis of the MSSM Higgs sector CP violation at photon colliders including the chargino loop contributions in the regime tan beta less than or similar to 20, where the CP violating mixing in the neutral Higgs sector is very strongly influenced by the scalar top loop, more so than the chargino and neutralino ones. However, the CP violating phases of the higgsino and wino mass parameters may still generate direct CP violation in gamma gamma -> H-i. In this process, the CP violating phenomena become very rich, and thus we study the production rates and polarization asymmetries in the Higgs production in detail. Photon colliders with high luminosity and well controlled polarized initial photon beams are indispensable in determining the CP properties of neutral Higgs bosons.

  
  

  

• Antisymmetric rank-2 tensor unparticle physics

  Title	: Antisymmetric rank-2 tensor unparticle physics
  Journal	: PHYSICAL REVIEW D, 2007

  
  

  논문

  NUMBER	P07047
  AUTHOR	Ko, P.,Wu, Xiao-Hong
  TITLE	Antisymmetric rank-2 tensor unparticle physics
  ARCHIVE	arXiv:0709.0629
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2007
  ABSTRACT	We present the phenomenology of antisymmetric rank-2 tensor unparticle operator OU,A(mu nu) with scaling dimension dU. We consider the physical effects of operator OU,A(mu nu) in Z(0) boson invisible decays Z(0)-> U, Z(0)-> b (b) over bar channel, the electroweak precision observable S parameter, and the muon anomalous magnetic dipole moment. The Z(0) boson invisible decay gives a very stringent constraint in the (Lambda U,MU) plane, and only small r equivalent to Lambda U/MU less than or similar to 0.1 is favored, when Lambda U is order of several 100 GeV. When the phenomenological parameter mu, which parameterizes the scale invariance breaking, goes to 0, the S parameter and the muon (g-2) diverge for 1 < dU < 2, while for nonzero mu, there will be constraints on (Lambda U,MU) which are more stringent than those obtained from collider experiments.

  
  

  

• String-derived D-4 flavor symmetry and phenomenological implications

  Title	: String-derived D-4 flavor symmetry and phenomenological implications
  Journal	: PHYSICAL REVIEW D, 2007

  
  

  논문

  NUMBER	P07015
  AUTHOR	Ko, Pyungwon
  TITLE	String-derived D-4 flavor symmetry and phenomenological implications
  ARCHIVE	0704.2807
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2007
  ABSTRACT	In this paper we show how some flavor symmetries may be derived from the heterotic string, when compactified on a 6D orbifold. In the body of the paper we focus on the D-4 family symmetry, recently obtained in Z(3)xZ(2) orbifold constructions. We show how this flavor symmetry constrains fermion masses, as well as the soft SUSY breaking mass terms. Flavor symmetry breaking can generate the hierarchy of fermion masses and at the same time the flavor symmetry suppresses large flavor changing neutral current processes.

  
  

  

• MSSM anatomy of the polarization puzzle in B ->phi K-* decays

  Title	: MSSM anatomy of the polarization puzzle in B ->phi K-* decays
  Journal	: PHYSICAL REVIEW D, 2006

  
  

  논문

  NUMBER	P05065
  AUTHOR	Ko, P
  TITLE	MSSM anatomy of the polarization puzzle in B ->phi K-* decays
  ARCHIVE	hep-ph/0511129
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2006
  ABSTRACT	We analyze the B ->phi K-* polarization puzzle in the minimal supersymmetric standard model (MSSM) including the neutral Higgs boson (NHB) contributions. To calculate the nonfactorizable contributions to the hadronic matrix elements of operators, we have used the QCD factorization framework to the alpha(s) order. It is shown that the recent experimental results of the polarization fractions in B ->phi K-* decays, which are difficult to be explained in SM, could be explained in MSSM if there are flavor nondiagonal squark mass matrix elements of 2nd and 3rd generations, which also satisfy all relevant constraints from known experiments (B -> X-s gamma,B-s ->mu(+)mu(-),B -> X-s mu(+)mu(-),B -> X(s)g,Delta M-s, etc.). We have shown in detail that the experimental results can be accommodated with the flavor nondiagonal mass insertion of chirality RL, RL+LR, RR, or LL+RR when the NHB contributions as well as O(alpha(s)) corrections of hadronic matrix elements of operators are included. However, the branching ratios for the decay are smaller than the experimental measurements.

  
  

  

• B-s ->mu(+)mu(-) and the upward-going muon flux from the WIMP annihilation in the sun or the earth

  Title	: B-s ->mu(+)mu(-) and the upward-going muon flux from the WIMP annihilation in the sun or the earth
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2005

  
  

  논문

  NUMBER	P05029
  AUTHOR	Ko, PW
  TITLE	B-s ->mu(+)mu(-) and the upward-going muon flux from the WIMP annihilation in the sun or the earth
  ARCHIVE	hep-ph/0506115
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2005
  ABSTRACT	We consider the upward-going muon flux due to the WIMP annihilations in the cores of the sun and the earth, including the upper bound on the branching ratio for B-s -> mu(+)mu(-) decay. We find that the constraint from B-s -> mu(+)mu(-) is very strong in most parameter space, and exclude the supergravity parameter space regions where the expected upward-going muon fluxes are within the expected reach of IceCube.

  
  

  

• Re(epsilon /epsilon(K)) versus B-d ->phi K-S CP asymmetry

  Title	: Re(epsilon /epsilon(K)) versus B-d ->phi K-S CP asymmetry
  Journal	: PHYSICAL REVIEW D, 2005

  
  

  논문

  NUMBER	P05019
  AUTHOR	Ko, P,Park, JH
  TITLE	Re(epsilon /epsilon(K)) versus B-d ->phi K-S CP asymmetry
  ARCHIVE	hep-ph/0503102
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2005
  ABSTRACT	In a SUSY GUT seesaw scenario, the largeness of the atmospheric neutrino mixing can reflect itself into an enhanced flavor changing mixing of beauty and strange right-handed scalar quarks. If the CP violating phase in such down-type squark RR insertion is the main source of CP asymmetry in B-d->phi K-S and the gluino contributions to K-0-(K) over bar (0) and B-0-(B) over bar (0) mixing are negligible, there is a correlation between Re (epsilon()/epsilon(K)) and B-d->phi K-S CP asymmetry, in addition to that with the strange quark CEDM. The current data on Re (epsilon()/epsilon(K))=(16.7 +/- 2.6)x10(-4) imply that S-phi K should be greater than similar to 0.5(0.25) for mu tan beta=1(5) TeV, assuming the RR dominance in b -> s transition and the minimal supergravity type boundary conditions for soft parameters.

  
  

  

• Direct detection of neutralino dark matter in supergravity

  Title	: Direct detection of neutralino dark matter in supergravity
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2005

  
  

  논문

  NUMBER	P05030
  AUTHOR	Ko, P
  TITLE	Direct detection of neutralino dark matter in supergravity
  ARCHIVE	hep-ph/0505019
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2005
  ABSTRACT	The direct detection of neutralino dark matter is analysed in general supergravity scenarios, where non-universal soft scalar and gaugino masses can be present. In particular, the theoretical predictions for the neutralino-nucleon cross section are studied and compared with the sensitivity of dark matter detectors. We take into account the most recent astrophysical and experimental constraints on the parameter space, including the current limit on B(B-s(0) -> mu(+)mu(-)). The latter puts severe limitations on the dark matter scattering cross section, ruling out most of the regions that would be within the reach of present experiments. We show how this constraint can be softened with the help of appropriate choices of non-universal parameters which increase the Higgsino composition of the lightest neutralino and minimise the chargino contribution to the b -> s transition.

  
  

  

• Lepton masses and mixing angles from heterotic orbifold models

  Title	: Lepton masses and mixing angles from heterotic orbifold models
  Journal	: PHYSICAL REVIEW D, 2005

  
  

  논문

  NUMBER	P05020
  AUTHOR	Ko, P,Park, JH
  TITLE	Lepton masses and mixing angles from heterotic orbifold models
  ARCHIVE	hep-ph/0503029
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2005
  ABSTRACT	We systematically study the possibility for realizing realistic values of lepton mass ratios and mixing angles by using only renormalizable Yukawa couplings derived from the heterotic Z(6)-I orbifold. We assume one pair of up and down sector Higgs fields. We consider both the Dirac neutrino mass scenario and the seesaw scenario with degenerate right-handed majorana neutrino masses. It is found that realistic values of the charged lepton mass ratios, m(e)/m(tau) and m(mu)/m(tau), the neutrino mass squared difference ratio, Delta m(31)(2)/Delta m(21)(2), and the lepton mixing angles can be obtained in certain cases.

  
  

  

• Color-evaporation-model calculation of e plus e- J/y plus cc- plus X at s=10. 6 GeV

  Title	: Color-evaporation-model calculation of e plus e- J/y plus cc- plus X at s=10. 6 GeV
  Journal	: PHYSICAL REVIEW D, 2005

  
  

  논문

  NUMBER
  AUTHOR	Ko, P
  TITLE	Color-evaporation-model calculation of e plus e- J/y plus cc- plus X at s=10. 6 GeV
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 2005
  ABSTRACT	Measurements by Belle Collaboration of the cross section for inclusive J/y production in e(c)(+e- annihilation have been a serious challenge to current heavy-quarkonium theory. In particular, the measured cross sections for exclusive J/y+h) and inclusive J/y+c (c) over bar +X differ from nonrelativistic QCD predictions by an order of magnitude. In order to check if other available alternative theories can resolve such a large discrepancy, we calculate the cross section for inclusive J/y+c (c) over bar +X based on the color-evaporation model. As a phenomenological model, the color-evaporation model is still employed to predict cross sections for inclusive quarkonium production in various processes. Our results show that the color-evaporation-model prediction is even smaller than the nonrelativistic QCD prediction by an order of magnitude. The resultant color-evaporation-model prediction for the J/y+c (c) over bar +X fraction in the inclusive J/y production cross section is 0.049, while the empirical value measured by Belle Collaboration is 0.82.

  
  

  

• Neutralino dark matter scattering and B-s ->mu(+)mu(-) in SUSY models

  Title	: Neutralino dark matter scattering and B-s ->mu(+)mu(-) in SUSY models
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2005

  
  

  논문

  NUMBER	P17139
  AUTHOR	Baek, S,Kim, YG,Ko, P
  TITLE	Neutralino dark matter scattering and B-s ->mu(+)mu(-) in SUSY models
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2005
  ABSTRACT	It is pointed out that there is a strong correlation between the neutralino dark matter scattering cross section sigma((chi) over tildep) and the branching ratio for B-s --> mu(+)mu(-) within minimal supergravity (mSUGRA) and its extensions. This correlation arises mainly from tan beta and heavy neutral Higgs mass dependence, and shows a nice interplay between vastly different two observables within supersymmetric models. Current upper limit on B(Bs --> mu(+)mu(-)) < 5.8 x 10(-7) excludes substantial parameter space where sigma(<(chi)over tilde>p) is within the CDMS sensitivity region.

  
  

  

• SUSY breaking mediation mechanisms and (g-2)mu, B -> X-s gamma, B -> X(s)l(+)l(-) and B-s -> mu(+)mu(-)

  Title	: SUSY breaking mediation mechanisms and (g-2)mu, B -> X-s gamma, B -> X(s)l(+)l(-) and B-s -> mu(+)mu(-)
  Journal	: JOURNAL OF HIGH ENERGY PHYSICS, 2003

  
  

  논문

  NUMBER	P02065
  AUTHOR	Ko, P,Baek, S
  TITLE	SUSY breaking mediation mechanisms and (g-2)mu, B -> X-s gamma, B -> X(s)l(+)l(-) and B-s -> mu(+)mu(-)
  ARCHIVE	hep-ph/0208112
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 2003
  ABSTRACT	We show that there are qualitative differences in correlations among (g - 2)(mu), B --> X-s gamma, B --> X(s)l(+)l(-) and B-s --> mu(+)mu(-) in various SUSY breaking mediation mechanisms: minimal supergravity (mSUGRA), gauge mediation (GMSB), anomaly mediation (AMSB), gaugino mediation ((g) over tilde MSB), weakly and strongly interacting string theories, and D brane models. After imposing the direct search limits on the Higgs boson and SUSY particle search limits and B --> X(s)gamma branching ratio, we find all the scenarios can accommodate the a(mu) = (g - 2)(mu)/2 in the range of (a few tens) x 10(-10), and predict that the branching ratio for B --> X(s)l(+)l(-) can differ from the standard model (SM) prediction by +/-20% but no more. On the other hand, the B-s --> mu(+)mu(-) is sensitive to the SUSY breaking mediation mechanisms through the pseudoscalar and stop masses (m(A) and m((t) over tilde1)), and the stop mixing angle. In the GMSB with a small messenger number, the AMSB, the (g) over tilde MSB and the noscale scenarios, one finds that B(B-s --> mu(+)mu(-)) less than or similar to 2 x 10(-8), which is below the search limit at the Tevatron Run II. Only the mSUGRA or string inspired models can generate a large branching ratio for this decay.

  
  

  

• Implications on supersymmetry-breaking mediation mechanisms from observing B-s ->mu(+)mu(-) and the muon g-2

  Title	: Implications on supersymmetry-breaking mediation mechanisms from observing B-s ->mu(+)mu(-) and the muon g-2
  Journal	: PHYSICAL REVIEW LETTERS, 2002

  
  

  논문

  NUMBER
  AUTHOR	Baek, S,Ko, P
  TITLE	Implications on supersymmetry-breaking mediation mechanisms from observing B-s ->mu(+)mu(-) and the muon g-2
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2002
  ABSTRACT	We consider B-s-->mu(+)mu(-) and the muon (g-2)(mu) in various supersymmetry-breaking mediation mechanisms. If the decay B-s-->mu(+)mu(-) is observed at Tevatron Run II with a branching ratio larger than similar to2x10(-8), the noscale supergravity (including the gaugino mediation), the gauge mediation scenario with a small number of messenger fields and low messenger scale, and a class of anomaly mediation scenarios will be excluded, even if they can accommodate a large muon (g-2)(mu). On the other hand, the minimal supergravity scenario and similar mechanisms derived from string models can accommodate this observation.

  
  

  

• Muon anomalous magnetic moment from effective supersymmetry

  Title	: Muon anomalous magnetic moment from effective supersymmetry
  Journal	: EUROPEAN PHYSICAL JOURNAL C, 2002

  
  

  논문

  NUMBER	P02007
  AUTHOR	Baek, S,Ko, P
  TITLE	Muon anomalous magnetic moment from effective supersymmetry
  ARCHIVE	hep-ph/0203251
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL C, 2002
  ABSTRACT	We present a detailed analysis on the possible maximal value of the union (g - 2)(mu) equivalent to 2alpha(mu) within the context of effective SUSY models with R parity conservation. First of all, mixing among the second susy and the third family sleptons can contribute at one loop level to alpha(mu)(SUSY) and r --> mugamma simultaneously. One finds that alpha(mu)(SUSY) can be as large as (10-20) x 10(-10) for any tan beta, imposing an upper limit on the r --> mugamma susy branching ratio. Furthermore, the two loop Barr-Zee type contributions to alpha(mu)(SUSY) may be significant for large tan,3, if a stop is light and p and At are large enough (- 0 (1) TeV). In this case, it is possible to have alpha(mu)(SUSY) up to O(10) x 10(-10) without conflicting with r --> lgamma. We conclude that the possible maximal value for alpha(mu)(SUSY) is about similar to20 x 10(-10) for any tan beta. Therefore the BNL experiment on the muon alpha(mu) can exclude the effective SUSY models only if the measured deviation is larger than similar to 30 x 10(-10).

  
  

  

• Possible new-physics signals in b -> s gamma and b -> sl(+)l(-)

  Title	: Possible new-physics signals in b -> s gamma and b -> sl(+)l(-)
  Journal	: NUCLEAR PHYSICS B, 1999

  
  

  논문

  NUMBER	P98021
  AUTHOR	Ko, P
  TITLE	Possible new-physics signals in b -> s gamma and b -> sl(+)l(-)
  ARCHIVE	hep-ph/9810336
  FILE
  JOURNAL	NUCLEAR PHYSICS B, 1999
  ABSTRACT	We consider possible new-physics contributions to b --> sl(+)l(-) assuming that new-physics modifies (chromo)magnetic and electric form factors in b --> s gamma* and b --> sg with the same chirality structure as in the standard model. Parametrizing the new-physics effects on b -->, s gamma* and b --> sg in terms of four real parameters, one finds that there is a large enough region of parameter space in which the measured branching ratio for B --> X(s)gamma can be accommodated, and the predicted CP violation effect could be as large as similar to 30%. Moreover, the branching ratio and the forward-backward asymmetry of a lepton in B --> X(s)l(+)l(-) and the tau polarization asymmetry in B --> X(s)tau(+)tau(-) can deviate from the SM predictions by a factor of similar to 2, which can be accessible at B-factories. We also discuss these observables in a specific class of supersymmetric models with gluino-mediated flavor changing neutral currents (FCNC). (C) 1999 Elsevier Science B.V.

  
  

  

• Mass matrix ansatz for degenerate neutrinos consistent with solar and atmospheric neutrino data

  Title	: Mass matrix ansatz for degenerate neutrinos consistent with solar and atmospheric neutrino data
  Journal	: PHYSICS LETTERS B, 1998

  
  

  논문

  NUMBER	P98027
  AUTHOR	Ko, P
  TITLE	Mass matrix ansatz for degenerate neutrinos consistent with solar and atmospheric neutrino data
  ARCHIVE	hep-ph/9706535
  FILE
  JOURNAL	PHYSICS LETTERS B, 1998
  ABSTRACT	We suggest mass matrices for neutrinos and charged leptons that can explain solar and atmospheric neutrino data. The resulting flavor mixing matrix V-nu has a property that (V-nu)(13) = 0, thus making nu(e) <-> nu(mu) and nu(mu) <-> nu(tau) oscillations to be effectively a two-channel problem. Phenomenological consequences of the lepton mass matrix ansatze are consistent with the current data on various type of neutrino oscillation experiments except the LSND measurement. Three neutrinos, being almost degenerate with Sigmam(nu i) less than or similar to 1 eV, can be a part of hot dark matter without any conflict with the constraint from neutrinoless double beta decay experiments. The nu(mu) <-> nu(tau) oscillation, sin(2)2 theta(mu tau), is predicted to be 0.86-0.97 with Delta m(mu tau)(2) similar or equal to 2 X 10(-3) eV(2), which is consistent with the atmospheric neutrino data and can be tested further at the planned MINOS and K2K experiments searching for nu(mu) --> nu(tau) oscillation. (C) 1998 Elsevier Science B.V. All rights reserved.

  
  

  

• Title	:	Resolving phenomenological problems with strongly-interacting-massive-particle models with dark vector resonances
  Journal	:	PHYSICAL REVIEW D, 98(1), 15034, 2018

  
  

  논문

  NUMBER
  AUTHOR	Choi, Soo-Min; Lee, Hyun Min; Ko, Pyungwon; Natale, Alexander
  TITLE	Resolving phenomenological problems with strongly-interacting-massive-particle models with dark vector resonances
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 98(1), 15034, 2018
  ABSTRACT	We consider a light dark matter candidate that is produced by the freeze-out mechanism with 3 -> 2 annihilations, the so-called strongly interacting massive particles (SIMPs). SIMPs are identified as dark pions in dark chiral perturbation theory (ChPT) in which both light mass and strong coupling needed for SIMPs can be realized by strong dynamics. In QCD-like theories with SU(3)(L) x SU(3)(R)/SU(3)(V) flavor symmetry, including dark vector mesons in the hidden local symmetry scheme, we illustrate that dark vector mesons unitarize the dark ChPT efficiently, thus determining the correct relic density condition within the validity of the dark ChPT.

  
  

  

• Title	:	Prospects for discovery and spin discrimination of dark matter in Higgs portal DM models and their extensions at 100 TeV pp collider
  Journal	:	EUROPEAN PHYSICAL JOURNAL C, 78(7), 595, 2018

  
  

  논문

  NUMBER
  AUTHOR	Dutta, Bhaskar; Kamon, Teruki; Ko, P.; Li, Jinmian
  TITLE	Prospects for discovery and spin discrimination of dark matter in Higgs portal DM models and their extensions at 100 TeV pp collider
  ARCHIVE
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL C, 78(7), 595, 2018
  ABSTRACT	We study the discovery and discriminating prospects of the Higgs portal dark matter (DM) models for scalar, fermion and vector DM and their extensions in proton-proton (pp) collisions. The t (t) over bar +DM associated production in dileptonic final states is considered, in which the stransverse mass of two leptons is found to be effective in suppressing the Standard Model backgrounds along with the missing transverse energy and the angle between two leptons. The distributions of missing transverse energy and polar angle between two leptons are used for a discrimination of the spin nature of DM. For the proposed benchmark points, the discovery/exclusion can be made with an integrated luminosity less than 1 ab(-1) given a 1% systematic uncertainty, while the spin discrimination require integrated luminosity of a few O(10) ab(-1) given a 0.5% systematic uncertainty. The DM phenomenology is also discussed. A consistent DM candidate can be obtained either by extending our model where the Higgs portal couples to excited dark states that decay into DM, or modifying the coupling form into pseudoscalar.

  
  

  

• Title	:	Particle, Astroparticle Physics and Cosmology in Dark Matter Models with Dark Gauge Symmetries
  Journal	:	JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 73(4), 449-465, 2018

  
  

  논문

  NUMBER
  AUTHOR	Ko, Pyungwon
  TITLE	Particle, Astroparticle Physics and Cosmology in Dark Matter Models with Dark Gauge Symmetries
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 73(4), 449-465, 2018
  ABSTRACT	In this review, I describe a class of dark matter (DM) models where DM is either stable due to unbroken dark gauge symmetries, or long-lived due to accidental global symmetries resulting from the underlying dark gauge symmetries. Within these models, I discuss various topics on DM in the context of particle and astroparticle physics and cosmology: DM thermal relic density and (in)direct detection, Higgs inflation assisted with Higgs portal interaction, dark radiation (DR), DM-DR interaction and suppression of the matter power spectrum at large k, strong first order phase transition and gravitational wave production, etc.. Especially I emphasize the importance of dark gauge symmetries, unitarity and renormalizability, and the limitation of the DM effective field theory (EFT) or simplified models for DM searches at high energy colliders, including the role of dark Higgs boson and dark gauge bosons.

  
  

  

• Title	:	Impact of the 125 GeV Higgs boson on singlet fermion dark matter searches at the LHC
  Journal	:	PHYSICAL REVIEW D, 98(5), 55031, 2018

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.; Li, Gang; Li, Jinmian
  TITLE	Impact of the 125 GeV Higgs boson on singlet fermion dark matter searches at the LHC
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, 98(5), 55031, 2018
  ABSTRACT	The search for singlet fermion dark matter at high-energy colliders is commonly analyzed with a singlet scalar mediator, which however violates the standard model (SM) gauge invariance, renormalizability and unitarity. These problems can be cured by introducing a mixing between the singlet scalar s and the SM Higgs boson h. Thus one has to consider two scalar mediators h(1) and h(2), where h(1) is identified as the discovered 125 GeV Higgs boson. As a specific example, we consider the dark matter (DM) search in the t (t) over bar + is not an element of(T) channel. According to the masses of dark matter and two scalar mediators, we classify the process into four cases. By investigating the total cross sections and differential distributions, we find that the contribution of the 125 GeV Higgs boson h(1) cannot be neglected in all cases and can even dominate once h(1) is on shell in dark matter production. Further, we study the impact of h(1) on the LHC bounds of dark matter searches in the hadronic and semileptonic channels with the integrated luminosity of 36 fb(-1). Finally we make a brief comment that h(1) should be also considered in the vector DM search at high-energy colliders.

  
  

  

• Title	:	Heavy quark-philic scalar dark matter with a vector-like fermion portal
  Journal	:	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 7, 8, 2018

  
  

  논문

  NUMBER
  AUTHOR	Baek, Seungwon; Ko, Pyungwon; Wu, Peiwen
  TITLE	Heavy quark-philic scalar dark matter with a vector-like fermion portal
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 7, 8, 2018
  ABSTRACT	The absence of confirmed signal in dark matter (DM) direct detection (DD) may suggest weak interaction strengths between DM and the abundant constituents inside nucleon, i.e. gluons and valence light quarks. In this work we consider a real scalar dark matter S interacting only with SU(2)(L) singlet Up-type quarks U-i, = uR, c(R), t(R) via a vector like fermion 0 which has the same quantum number as U-i. The DM-nucleon scattering can proceed through both h-mediated Higgs portal (HP) and psi-mediated vector-like portal (VLP), in which HP can receive sizable radiative corrections through the new fermions. We first study the separate constraints on the new Yukawa couplings y(i) and find that the constraints of XENON1T results are strong on y(1) from VLP scattering and on y(3) from its radiative contributions to HP scattering. Since both DM-light quark interactions and HP have been well studied in the existing literature, we move forward to focus on DM heavy quark interactions. Since there is no valence c, t quark inside nucleons at mu(had) similar to 1 GeV, y(2), y(3) interactions are manifested in DM-gluon scattering at loop level. We find that renormalization group equation (RGE) and heavy quark threshold effects are important if one calculates the DM-nucleon scattering rate apsi at Mad 1 GeV while constructing the effective theory at mu(LEFT) similar to m(Z). For the benchmarks y(3) = 0.5, y(2) = 0.5,1, 3, combined results from Omega(DM)h(2) similar or equal to 0.12, XENON1T, Fermi-LAT, 13 TeV LHC data have almost excluded m(s) < m(t)/2 when only DM-{c, t} interactions are considered. FCNC of top quark can be generated at both tree level t -> psi(*),S -> cSS and loop level t -> c + gamma/g/Z, of which the branching fractions are typically below 10(-9) after passing the other constraints, which are still safe from the current top quark width measurements.

  
  

  

• Title	:	Gravitational waves from first order electroweak phase transition in models with the U(1)(X) gauge symmetry
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, 6, 88, 2018

  
  

  논문

  NUMBER	P18013
  AUTHOR	Hashino, Katsuya; Kakizaki, Mitsuru; Kanemura, Shinya; Ko, Pyungwon; Matsui, Toshinori
  TITLE	Gravitational waves from first order electroweak phase transition in models with the U(1)(X) gauge symmetry
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, 6, 88, 2018
  ABSTRACT	We consider a standard model extension equipped with a dark sector where the U(1)(X) Abelian gauge symmetry is spontaneously broken by the dark Higgs mechanism. In this framework, we investigate patterns of the electroweak phase transition as well as those of the dark phase transition, and examine detectability of gravitational waves (GWs) generated by such strongly first order phase transition. It is pointed out that the collider bounds on the properties of the discovered Higgs boson exclude a part of parameter space that could otherwise generate detectable GWs. After imposing various constraints on this model, it is shown that GWs produced by multi-step phase transitions are detectable at future space-based interferometers, such as LISA and DECIGO, if the dark photon is heavier than 25 GeV. Furthermore, we discuss the complementarity of dark photon searches or dark matter searches with the GW observations in these models with the dark gauge symmetry.

  
  

  

• Title	:	Strong first order EWPT & strong gravitational waves in Z(3)-symmetric singlet scalar extension
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS no.2, 115. 2018.

  
  

  논문

  NUMBER	P17047
  AUTHOR	Kang, Zhaofeng; Ko, P.; Matsui, Toshinori
  TITLE	Strong first order EWPT & strong gravitational waves in Z(3)-symmetric singlet scalar extension
  ARCHIVE	arXiv:1706.09721
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS no.2, 115. 2018.
  ABSTRACT

  
  

  

• Title	:	Simplified DM models with the full SM gauge symmetry: the case of t-channel colored scalar mediators
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS no.1, 86. 2017.

  
  

  논문

  NUMBER	Q16012
  AUTHOR	Ko, P.; Natale, Alexander; Park, Myeonghun; Yokoya, Hiroshi
  TITLE	Simplified DM models with the full SM gauge symmetry: the case of t-channel colored scalar mediators
  ARCHIVE	arXiv:1605.07058
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS no.1, 86. 2017.
  ABSTRACT

  
  

  

• Title	:	Higgs-portal assisted Higgs inflation with a sizeable tensor-to-scalar ratio
  Journal	:	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS no.2, 3. 2017

  
  

  논문

  NUMBER	Q16017
  AUTHOR	Kim, Jinsu; Ko, Pyungwon; Park, Wan-Il
  TITLE	Higgs-portal assisted Higgs inflation with a sizeable tensor-to-scalar ratio
  ARCHIVE	1405.1635
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS no.2, 3. 2017
  ABSTRACT

  
  

  

• Title	:	Interference effects of two scalar boson propagators on the LHC search for the singlet fermion DM
  Journal	:	PHYSICS LETTERS B v.765, 53-61p. 2017.

  
  

  논문

  NUMBER	P16076
  AUTHOR	Ko, P.; Li, Jinmian
  TITLE	Interference effects of two scalar boson propagators on the LHC search for the singlet fermion DM
  ARCHIVE	arXiv:1610.03997
  FILE
  JOURNAL	PHYSICS LETTERS B v.765, 53-61p. 2017.
  ABSTRACT

  
  

  

• Title	:	Asymmetric dark matter bound state
  Journal	:	PHYSICAL REVIEW D v.95(4), 043540. 2017.

  
  

  논문

  NUMBER	P16027
  AUTHOR	Bi, Xiao-Jun; Kang, Zhaofeng; Ko, P.; Li, Jinmian; Li, Tianjun
  TITLE	Asymmetric dark matter bound state
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D v.95(4), 043540. 2017.
  ABSTRACT

  
  

  

• Title	:	Revisiting T2KK and T2KO physics potential and nu mu-(nu)over-bar mu beam ratio
  Journal	:	EUROPEAN PHYSICAL JOURNAL C v.77(3), 138. 2017.

  
  

  논문

  NUMBER	P16036
  AUTHOR	Hagiwara, Kaoru; Ko, Pyungwon; Okamura, Naotoshi; Takaesu, Yoshitaro
  TITLE	Revisiting T2KK and T2KO physics potential and nu mu-(nu)over-bar mu beam ratio
  ARCHIVE
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL C v.77(3), 138. 2017.
  ABSTRACT

  
  

  

• Title	:	Gravitational waves and Higgs boson couplings for exploring first order phase transition in the model with a singlet scalar field
  Journal	:	PHYSICS LETTERS B v.766, 49-54p. 2017.

  
  

  논문

  NUMBER	P16065
  AUTHOR	Hashino, Katsuya; Kakizaki, Mitsuru; Kanemura, Shinya; Ko, Pyungwon; Matsui, Toshinori
  TITLE	Gravitational waves and Higgs boson couplings for exploring first order phase transition in the model with a singlet scalar field
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B v.766, 49-54p. 2017.
  ABSTRACT

  
  

  

• Title	:	Minimal renormalizable simplified dark matter model with a pseudoscalar mediator
  Journal	:	PHYSICAL REVIEW D v.95(7), 075011. 2017.

  
  

  논문

  NUMBER	P17004
  AUTHOR	Baek, Seungwon; Ko, P.; Li, Jinmian
  TITLE	Minimal renormalizable simplified dark matter model with a pseudoscalar mediator
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D v.95(7), 075011. 2017.
  ABSTRACT

  
  

  

• Title	:	Residual non-Abelian dark matter and dark radiation
  Journal	:	PHYSICS LETTERS B v.768,12-17p. 2017.

  
  

  논문

  NUMBER	P16074
  AUTHOR	Ko, P.; Tang, Yong
  TITLE	Residual non-Abelian dark matter and dark radiation
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B v.768,12-17p. 2017.
  ABSTRACT

  
  

  

• Title	:	Explaining B -> K-(*())l(+)l(-) anomaly by radiatively induced coupling in U(1)(mu-tau) gauge symmetry
  Journal	:	PHYSICAL REVIEW D v.95(11), 111701.2017.

  
  

  논문

  NUMBER	P17010
  AUTHOR	Ko, P.; Nomura, Takaaki; Okada, Hiroshi
  TITLE	Explaining B -> K-(*())l(+)l(-) anomaly by radiatively induced coupling in U(1)(mu-tau) gauge symmetry
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D v.95(11), 111701.2017.
  ABSTRACT

  
  

  

• Title	:	Probing a new strongly interacting sector via composite diboson resonances
  Journal	:	PHYSICAL REVIEW D v.95(11), 115034. 2017.

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.; Yu, Chaehyun; Yuan, Tzu-Chiang
  TITLE	Probing a new strongly interacting sector via composite diboson resonances
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D v.95(11), 115034. 2017.
  ABSTRACT

  
  

  

• Title	:	LHCb anomaly and B physics in flavored Z models with flavored Higgs doublets
  Journal	:	PHYSICAL REVIEW D v.95(11), 115040. 2017

  
  

  논문

  NUMBER	P17015
  AUTHOR	Ko, P.; Omura, Yuji; Shigekami, Yoshihiro; Yu, Chaehyun
  TITLE	LHCb anomaly and B physics in flavored Z models with flavored Higgs doublets
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D v.95(11), 115040. 2017
  ABSTRACT

  
  

  

• Title	:	A flavor dependent gauge symmetry, predictive radiative seesaw and LHCb anomalies
  Journal	:	PHYSICS LETTERS B v.772, 547-552p. 2017

  
  

  논문

  NUMBER	P17007
  AUTHOR	Ko, P.; Nomura, Takaaki; Okada, Hiroshi
  TITLE	A flavor dependent gauge symmetry, predictive radiative seesaw and LHCb anomalies
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B v.772, 547-552p. 2017
  ABSTRACT

  
  

  

• Title	:	Characterizing Higgs portal dark matter models at the ILC
  Journal	:	EUROPEAN PHYSICAL JOURNAL C. v.77(9), 652. 2017.

  
  

  논문

  NUMBER	P17033
  AUTHOR	Kamon, Teruki; Ko, P.; Li, Jinmian
  TITLE	Characterizing Higgs portal dark matter models at the ILC
  ARCHIVE
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL C. v.77(9), 652. 2017.
  ABSTRACT

  
  

  

• Title	:	Hidden charged dark matter and chiral dark radiation
  Journal	:	PHYSICS LETTERS B v.773, 513-520p. 2017.

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.; Nagata, Natsumi; Tang, Yong
  TITLE	Hidden charged dark matter and chiral dark radiation
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B v.773, 513-520p. 2017.
  ABSTRACT

  
  

  

• Title	:	Phenomenology of dark matter in chiral U(1)(X) dark sector
  Journal	:	PHYSICAL REVIEW (2016) D94 no.11 115015

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.; Nomura, Takaaki
  TITLE	Phenomenology of dark matter in chiral U(1)(X) dark sector
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW (2016) D94 no.11 115015
  ABSTRACT

  
  

  

• Title	:	New avenues to heavy right-handed neutrinos with pair production at hadronic colliders
  Journal	:	PHYSICAL REVIEW D93 (2016) no. 7, 075037

  
  

  논문

  NUMBER
  AUTHOR	Kang, Zhaofeng; Ko, P.; Li, Jinmian
  TITLE	New avenues to heavy right-handed neutrinos with pair production at hadronic colliders
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D93 (2016) no. 7, 075037
  ABSTRACT

  
  

  

• Title	:	Higgs precision study of the 750 GeV diphoton resonance and the 125 GeV standard model Higgs boson with Higgs-singlet mixing
  Journal	:	PHYSICAL REVIEW D94 (2016) no.3, 033010

  
  

  논문

  NUMBER
  AUTHOR	Cheung, Kingman; Ko, P.; Lee, Jae Sik; Park, Jubin; Tseng, Po-Yan
  TITLE	Higgs precision study of the 750 GeV diphoton resonance and the 125 GeV standard model Higgs boson with Higgs-singlet mixing
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D94 (2016) no.3, 033010
  ABSTRACT

  
  

  

• Title	:	Confronting a new three-loop seesaw model with the 750 GeV diphoton excess
  Journal	:	PHYSICAL REVIEW D v.94 no.1 (2016) 013009

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.; Nomura, Takaaki; Okada, Hiroshi; Orikasa, Yuta
  TITLE	Confronting a new three-loop seesaw model with the 750 GeV diphoton excess
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D v.94 no.1 (2016) 013009
  ABSTRACT

  
  

  

• Title	:	Flavor SU (3) properties of beauty tetraquark states with three different light quarks
  Journal	:	PHYSICS LETTERS B v.761 p.92-97 (2016)

  
  

  논문

  NUMBER
  AUTHOR	Xiao-Gang He, Pyungwon Ko
  TITLE	Flavor SU (3) properties of beauty tetraquark states with three different light quarks
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B v.761 p.92-97 (2016)
  ABSTRACT

  
  

  

• Title	:	Dark sector shining through 750 GeV dark Higgs boson at the LHC
  Journal	:	PHYSICS LETTERS B v.758 p.205-211 (2016)

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.; Nomura, Takaaki
  TITLE	Dark sector shining through 750 GeV dark Higgs boson at the LHC
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B v.758 p.205-211 (2016)
  ABSTRACT

  
  

  

• Title	:	Beyond the dark matter effective field theory and a simplified model approach at colliders
  Journal	:	PHYSICS LETTERS B v.756 p.289-294 (2016)

  
  

  논문

  NUMBER
  AUTHOR	Baek, Seungwon; Ko, P.; Park, Myeonghun; Park, Wan-Il; Yu, Chaehyun
  TITLE	Beyond the dark matter effective field theory and a simplified model approach at colliders
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B v.756 p.289-294 (2016)
  ABSTRACT

  
  

  

• Title	:	Dark Higgs channel for Fermi GeV gamma-ray excess
  Journal	:	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS 2 (2016) 011

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.; Tang, Yong
  TITLE	Dark Higgs channel for Fermi GeV gamma-ray excess
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS 2 (2016) 011
  ABSTRACT

  
  

  

• Title	:	Top-philic scalar Dark Matter with a vector-like fermionic top partner
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS 10 (2016) 117

  
  

  논문

  NUMBER
  AUTHOR	Baek, Seungwon; Ko, Pyungwon; Wu, Peiwen
  TITLE	Top-philic scalar Dark Matter with a vector-like fermionic top partner
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS 10 (2016) 117
  ABSTRACT

  
  

  

• Title	:	Search for Higgs portal DM at the ILC
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS 8 (2016) 109

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.; Yokoya, Hiroshi
  TITLE	Search for Higgs portal DM at the ILC
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS 8 (2016) 109
  ABSTRACT

  
  

  

• Title	:	Diphoton excess at 750 GeV in leptophobic U(1) model inspired by E-6 GUT
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS 4 (2016) 098

  
  

  논문

  NUMBER
  AUTHOR	Ko, P.; Omura, Yuji; Yu, Chaehyun
  TITLE	Diphoton excess at 750 GeV in leptophobic U(1) model inspired by E-6 GUT
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS 4 (2016) 098
  ABSTRACT

  
  

  

• Title	:	AdS/QCD approach to the scale-invariant extension of the standard model with a strongly interacting hidden sector
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS 1608 (2016) 094

  
  

  논문

  NUMBER
  AUTHOR	Hatanaka, Hisaki; Jung, Dong-Won; Ko, Pyungwon
  TITLE	AdS/QCD approach to the scale-invariant extension of the standard model with a strongly interacting hidden sector
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS 1608 (2016) 094
  ABSTRACT

  
  

  

• Title	:	Light dark photon and fermionic dark radiation for the Hubble constant and the structure formation
  Journal	:	PHYSICS LETTERS B 762 (2016) 462

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Yong Tang
  TITLE	Light dark photon and fermionic dark radiation for the Hubble constant and the structure formation
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B 762 (2016) 462
  ABSTRACT

  
  

  

• Title	:	New Physics Opportunities in the Boosted Di-Higgs-Boson Plus Missing Transverse Energy Signature
  Journal	:	PHYSICAL REVIEW LETTERS v.116 no.13 (2016) 131801

  
  

  논문

  NUMBER
  AUTHOR	Kang, Zhaofeng; Ko, P.; Li, Jinmian
  TITLE	New Physics Opportunities in the Boosted Di-Higgs-Boson Plus Missing Transverse Energy Signature
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS v.116 no.13 (2016) 131801
  ABSTRACT

  
  

  

• Title	:	SU(2)(L) x SU(2)(R) minimal dark matter with 2 TeV W
  Journal	:	PHYSICS LETTERS B, v.753 (2016) 612-618

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Nomura, T
  TITLE	SU(2)(L) x SU(2)(R) minimal dark matter with 2 TeV W
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, v.753 (2016) 612-618
  ABSTRACT

  
  

  

• Title	:	IceCube events from heavy DM decays through the right-handed neutrino portal
  Journal	:	PHYSICS LETTERS B, v.751 (2015) 81-88

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Tang, Y
  TITLE	IceCube events from heavy DM decays through the right-handed neutrino portal
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, v.751 (2015) 81-88
  ABSTRACT

  
  

  

• Title	:	Bounds on Higgs-portal models from the LHC Higgs data
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.10 (2015) 057

  
  

  논문

  NUMBER
  AUTHOR	Cheung, K; Ko, P; Lee, JS; Tseng, PY
  TITLE	Bounds on Higgs-portal models from the LHC Higgs data
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.10 (2015) 057
  ABSTRACT

  
  

  

• Title	:	Local Z(2) scalar dark matter model confronting galactic GeV-scale gamma-ray
  Journal	:	PHYSICS LETTERS B, v.747 (2015) 255-259

  
  

  논문

  NUMBER
  AUTHOR	Baek, S; Ko, P; Park, WI
  TITLE	Local Z(2) scalar dark matter model confronting galactic GeV-scale gamma-ray
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, v.747 (2015) 255-259
  ABSTRACT

  
  

  

• Title	:	Accidental dark matter: Case in the scale invariant local B - L model
  Journal	:	PHYSICAL REVIEW D, v.91 no.11 (2015) 115017

  
  

  논문

  NUMBER
  AUTHOR	Guo, J; Kang, ZF; Ko, P; Orikasa, Y
  TITLE	Accidental dark matter: Case in the scale invariant local B - L model
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, v.91 no.11 (2015) 115017
  ABSTRACT

  
  

  

• Title	:	Higgs and dark matter physics in the type-II two-Higgs-doublet model inspired by E-6 GUT
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.6 (2015) 034

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Omura, Y; Yu, C
  TITLE	Higgs and dark matter physics in the type-II two-Higgs-doublet model inspired by E-6 GUT
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.6 (2015) 034
  ABSTRACT

  
  

  

• Title	:	Natural X-ray lines from the low scale supersymmetry breaking
  Journal	:	PHYSICS LETTERS B, v.742 (2015) 249-255

  
  

  논문

  NUMBER
  AUTHOR	Kang, ZF; Ko, P; Li, TJ; Liu, YD
  TITLE	Natural X-ray lines from the low scale supersymmetry breaking
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, v.742 (2015) 249-255
  ABSTRACT

  
  

  

• Title	:	AMS02 positron excess from decaying fermion DM with local dark gauge symmetry
  Journal	:	PHYSICS LETTERS B, v.741 (2015) 284-289

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Tang, Y
  TITLE	AMS02 positron excess from decaying fermion DM with local dark gauge symmetry
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, v.741 (2015) 284-289
  ABSTRACT

  
  

  

• Title	:	Galactic center gamma-ray excess in hidden sector DM models with dark gauge symmetries: local Z(3) symmetry as an example
  Journal	:	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, v.1 (2015) 023

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Tang, Y
  TITLE	Galactic center gamma-ray excess in hidden sector DM models with dark gauge symmetries: local Z(3) symmetry as an example
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, v.1 (2015) 023
  ABSTRACT

  
  

  

• Title	:	nu Lambda MDM: A model for sterile neutrino and dark matter reconciles cosmological and neutrino oscillation data after BICEP2
  Journal	:	PHYSICS LETTERS B, v.739 (2014) 62-67

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Tang, Y
  TITLE	nu Lambda MDM: A model for sterile neutrino and dark matter reconciles cosmological and neutrino oscillation data after BICEP2
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, v.739 (2014) 62-67
  ABSTRACT

  
  

  

• Title	:	Dark matter and dark force in the type-I inert 2HDM with local U(1)(H) gauge symmetry
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.11 (2014) 054

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Omura, Y; Yu, C
  TITLE	Dark matter and dark force in the type-I inert 2HDM with local U(1)(H) gauge symmetry
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.11 (2014) 054
  ABSTRACT

  
  

  

• Title	:	Hidden sector monopole, vector dark matter and dark radiation with Higgs portal
  Journal	:	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, v.10 (2014) 067

  
  

  논문

  NUMBER
  AUTHOR	Baek, S; Ko, P; Park, WI
  TITLE	Hidden sector monopole, vector dark matter and dark radiation with Higgs portal
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, v.10 (2014) 067
  ABSTRACT

  
  

  

• Title	:	Can Zee-Babu model implemented with scalar dark matter explain both Fermi-LAT 130 GeV gamma-ray excess and neutrino physics?
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.9 (2014) 153

  
  

  논문

  NUMBER
  AUTHOR	Baek, S; Ko, P; Okada, H; Senahaa, E
  TITLE	Can Zee-Babu model implemented with scalar dark matter explain both Fermi-LAT 130 GeV gamma-ray excess and neutrino physics?
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.9 (2014) 153
  ABSTRACT

  
  

  

• Title	:	Invisible Higgs decay width versus dark matter direct detection cross section in Higgs portal dark matter models
  Journal	:	PHYSICAL REVIEW D, v. 90 no.5 (2014) 055014

  
  

  논문

  NUMBER
  AUTHOR	Baek, S; Ko, P; Park, WI
  TITLE	Invisible Higgs decay width versus dark matter direct detection cross section in Higgs portal dark matter models
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, v. 90 no.5 (2014) 055014
  ABSTRACT

  
  

  

• Title	:	Higgs portal vector dark matter for GeV scale gamma-ray excess from galactic center
  Journal	:	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, v.9 (2014) 013

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Park, WI; Tang, Y
  TITLE	Higgs portal vector dark matter for GeV scale gamma-ray excess from galactic center
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, v.9 (2014) 013
  ABSTRACT

  
  

  

• Title	:	Renormalization group-induced phenomena of top pairs from four-quark effective operators
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.8 (2014) 120

  
  

  논문

  NUMBER
  AUTHOR	Jung, S; Ko, P; Yoon, YW; Yu, C
  TITLE	Renormalization group-induced phenomena of top pairs from four-quark effective operators
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.8 (2014) 120
  ABSTRACT

  
  

  

• Title	:	Correlation of top asymmetries: Loop versus tree origins
  Journal	:	PHYSICAL REVIEW D, v.90 no.3 (2014) 034007

  
  

  논문

  NUMBER
  AUTHOR	Jung, S; Ko, P; Yoon, YW; Yu, C
  TITLE	Correlation of top asymmetries: Loop versus tree origins
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, v.90 no.3 (2014) 034007
  ABSTRACT

  
  

  

• Title	:	Indirect and direct signatures of Higgs portal decaying vector dark matter for positron excess in cosmic rays
  Journal	:	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, v.6 (2014) 046

  
  

  논문

  NUMBER
  AUTHOR	Baek, S; Ko, P; Park, WI; Tang, Y
  TITLE	Indirect and direct signatures of Higgs portal decaying vector dark matter for positron excess in cosmic rays
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, v.6 (2014) 046
  ABSTRACT

  
  

  

• Title	:	Self-interacting scalar dark matter with local Z(3) symmetry
  Journal	:	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, v.5 (2014) 047

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Tang, Y
  TITLE	Self-interacting scalar dark matter with local Z(3) symmetry
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, v.5 (2014) 047
  ABSTRACT

  
  

  

• Title	:	Higgs-dilaton(radion) system confronting the LHC Higgs data
  Journal	:	PHYSICS LETTERS B, v.732 (2014) 364-372

  
  

  논문

  NUMBER
  AUTHOR	Jung, DW; Ko, P
  TITLE	Higgs-dilaton(radion) system confronting the LHC Higgs data
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, v.732 (2014) 364-372
  ABSTRACT

  
  

  

• Title	:	Higgs phenomenology in Type-I 2HDM with U(1)(H) Higgs gauge symmetry
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.1 (2014) 016

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Omura, Y; Yu, C
  TITLE	Higgs phenomenology in Type-I 2HDM with U(1)(H) Higgs gauge symmetry
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.1 (2014) 016
  ABSTRACT

  
  

  

• Title	:	Singlet portal extensions of the standard seesaw models to a dark sector with local dark symmetry
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.7 (2013) 013

  
  

  논문

  NUMBER
  AUTHOR	Baek, S; Ko, P; Park, WI
  TITLE	Singlet portal extensions of the standard seesaw models to a dark sector with local dark symmetry
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.7 (2013) 013
  ABSTRACT

  
  

  

• Title	:	Implications of LHC data on 125 GeV Higgs-like boson for the Standard Model and its various extensions
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.10 (2013) 225

  
  

  논문

  NUMBER
  AUTHOR	Choi, S; Jung, S; Ko, P
  TITLE	Implications of LHC data on 125 GeV Higgs-like boson for the Standard Model and its various extensions
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.10 (2013) 225
  ABSTRACT

  
  

  

• Title	:	Higgs portal vector dark matter: revisited
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.5 (2103) 036

  
  

  논문

  NUMBER
  AUTHOR	Baek, S; Ko, P; Park, WI; Senaha, E
  TITLE	Higgs portal vector dark matter: revisited
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.5 (2103) 036
  ABSTRACT

  
  

  

• Title	:	B -> D-(*())tau nu and B -> tau nu in chiral U(1) models with flavored multi Higgs doublets
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.3 (2013) 151

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Omura, Y; Yu, C
  TITLE	B -> D-(*())tau nu and B -> tau nu in chiral U(1) models with flavored multi Higgs doublets
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.3 (2013) 151
  ABSTRACT

  
  

  

• Title	:	Top A(FB) at the Tevatron vs. charge asymmetry at the LHC in chiral U(1) flavor models with flavored Higgs doublets
  Journal	:	EUROPEAN PHYSICAL JOURNAL C, v.73 no.1 (2013) 2269

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Omura, Y; Yu, C
  TITLE	Top A(FB) at the Tevatron vs. charge asymmetry at the LHC in chiral U(1) flavor models with flavored Higgs doublets
  ARCHIVE
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL C, v.73 no.1 (2013) 2269
  ABSTRACT

  
  

  

• Title	:	Vacuum structure and stability of a singlet fermion dark matter model with a singlet scalar messenger
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.11 (2012) 116

  
  

  논문

  NUMBER
  AUTHOR	Seungwon Baek, P. Ko, Wan-Il Park, Eibun Senaha
  TITLE	Vacuum structure and stability of a singlet fermion dark matter model with a singlet scalar messenger
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.11 (2012) 116
  ABSTRACT

  
  

  

• Title	:	A resolution of the flavor problem of two Higgs doublet models with an extra U(1)(H) symmetry for Higgs flavor
  Journal	:	PHYSICS LETTERS B, v.717 no.1-3 (2012) 202-206

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Omura, Y; Yu, C
  TITLE	A resolution of the flavor problem of two Higgs doublet models with an extra U(1)(H) symmetry for Higgs flavor
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, v.717 no.1-3 (2012) 202-206
  ABSTRACT

  
  

  

• Title	:	Simplified models for LHC new physics searches
  Journal	:	JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, v.39 no.10 (2012) 105005

  
  

  논문

  NUMBER
  AUTHOR	Alves, D; Arkani-Hamed, N; Arora, S; Bai, Y; Baumgart, M; Berger, J; Buckley, M; Butler, B; Chang, S; Cheng, HC; Cheung, C; Chivukula, RS; Cho, WS; Cotta, R; DAlfonso, M; El Hedri, S; Essig, R; Evans, JA; Fitzpatrick, L; Fox, P; Franceschini, R; Fre
  TITLE	Simplified models for LHC new physics searches
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, v.39 no.10 (2012) 105005
  ABSTRACT

  
  

  

• Title	:	Top forward-backward asymmetry and the CDF Wjj excess in leptophobic U(1) flavor models
  Journal	:	PHYSICAL REVIEW D, v.85 no.11 (2012) 115010

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Omura, Y; Yu, C
  TITLE	Top forward-backward asymmetry and the CDF Wjj excess in leptophobic U(1) flavor models
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, v.85 no.11 (2012) 115010
  ABSTRACT

  
  

  

• Title	:	Dijet resonance from leptophobic Z and light baryonic cold dark matter
  Journal	:	PHYSICS LETTERS B, v.710 no.1 (2012) 197-200

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Omura, Y; Yu, C
  TITLE	Dijet resonance from leptophobic Z and light baryonic cold dark matter
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, v.710 no.1 (2012) 197-200
  ABSTRACT

  
  

  

• Title	:	Light dark matter in leptophobic Z models
  Journal	:	PHYSICAL REVIEW D, v.85 no.3 (2012) 035022

  
  

  논문

  NUMBER
  AUTHOR	Gondolo, P; Ko, P; Omura, Y
  TITLE	Light dark matter in leptophobic Z models
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, v.85 no.3 (2012) 035022
  ABSTRACT

  
  

  

• Title	:	Mass dependent top forward-backward asymmetry in the effective Lagrangian approach: Addendum to Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron
  Journal	:	PHYSICS LETTERS B, v.708 no.1-2 (2012) 157-161

  
  

  논문

  NUMBER
  AUTHOR	Jung, DW; Ko, P; Lee, JS
  TITLE	Mass dependent top forward-backward asymmetry in the effective Lagrangian approach: Addendum to Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron
  ARCHIVE
  FILE
  JOURNAL	PHYSICS LETTERS B, v.708 no.1-2 (2012) 157-161
  ABSTRACT

  
  

  

• Title	:	Search for the Higgs portal to a singlet fermionic dark matter at the LHC
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.2 (2012) 047

  
  

  논문

  NUMBER
  AUTHOR	Baek, S; Ko, P; Park, WI
  TITLE	Search for the Higgs portal to a singlet fermionic dark matter at the LHC
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.2 (2012) 047
  ABSTRACT

  
  

  

• Title	:	Chiral U(1) flavor models and flavored Higgs doublets: the top FB asymmetry and the Wjj
  Journal	:	JOURNAL OF HIGH ENERGY PHYSICS, v.1 (2012) 147

  
  

  논문

  NUMBER
  AUTHOR	Ko, P; Omura, Y; Yu, C
  TITLE	Chiral U(1) flavor models and flavored Higgs doublets: the top FB asymmetry and the Wjj
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF HIGH ENERGY PHYSICS, v.1 (2012) 147
  ABSTRACT

  
  

  

• Title	:	Possible common origin of the top forward-backward asymmetry and the CDF Wjj excess
  Journal	:	PHYSICAL REVIEW D, v.84 no.5 (2011) 055027

  
  

  논문

  NUMBER
  AUTHOR	Jung, DW; Ko. P; Lee, JS
  TITLE	Possible common origin of the top forward-backward asymmetry and the CDF Wjj excess
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW D, v.84 no.5 (2011) 055027
  ABSTRACT

  
  

  

• Title	:	Scale invariant extension of the standard model with strongly interacting hidden sector
  Journal	:	Phys.Rev.Lett.106:141802,2011

  
  

  논문

  NUMBER
  AUTHOR	Taeil Hur, P. Ko
  TITLE	Scale invariant extension of the standard model with strongly interacting hidden sector
  ARCHIVE	arXiv:1103.2571
  FILE
  JOURNAL	Phys.Rev.Lett.106:141802,2011
  ABSTRACT

  
  

  

• Title	:	Supersymmetric U(1)B x U(1)L model with leptophilic and leptophobic cold dark matters
  Journal	:	Phys.Lett.B701:363-366,2011

  
  

  논문

  NUMBER
  AUTHOR	Pyungwon Ko, Yuji Omura
  TITLE	Supersymmetric U(1)B x U(1)L model with leptophilic and leptophobic cold dark matters
  ARCHIVE	arXiv:1012.4679
  FILE
  JOURNAL	Phys.Lett.B701:363-366,2011
  ABSTRACT

  
  

  

• Title	:	Electroweak symmetry breaking and cold dark matter from strongly interacting hidden sector
  Journal	:	Phys. Lett. B696 (2011) 262

  
  

  논문

  NUMBER
  AUTHOR	Taeil Hur, Dong-Won Jung, P. Ko, Jae Yong Lee
  TITLE	Electroweak symmetry breaking and cold dark matter from strongly interacting hidden sector
  ARCHIVE	arXiv:0709.1218 [hep-ph]
  FILE
  JOURNAL	Phys. Lett. B696 (2011) 262
  ABSTRACT

  
  

  

• Title	:	Longitudinal top polarization as a probe of a possible origin of forward-backward asymmetry of the top quark at the Tevatron
  Journal	:	Phys.Lett.B701:248-254,2011

  
  

  논문

  NUMBER
  AUTHOR	Dong-Won Jung, P. Ko, Jae Sik Lee
  TITLE	Longitudinal top polarization as a probe of a possible origin of forward-backward asymmetry of the top quark at the Tevatron
  ARCHIVE	arXiv:1011.5976
  FILE
  JOURNAL	Phys.Lett.B701:248-254,2011
  ABSTRACT

  
  

  

• Title	:	Inclusive double-quarkonium production at the Large Hadron Collider
  Journal	:	JHEP 1101:070,2011

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Chaehyun Yu, Jungil Lee
  TITLE	Inclusive double-quarkonium production at the Large Hadron Collider
  ARCHIVE	arXiv:1007.3095
  FILE
  JOURNAL	JHEP 1101:070,2011
  ABSTRACT

  
  

  

• Title	:	p p -> J/＼psi + ＼Upsilon + X as a clean probe to the quarkonium production mechanism
  Journal	:	Phys.Rev.D83:054015,2011

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Chaehyun Yu, Jungil Lee
  TITLE	p p -> J/＼psi + ＼Upsilon + X as a clean probe to the quarkonium production mechanism
  ARCHIVE	arXiv:1006.3846
  FILE
  JOURNAL	Phys.Rev.D83:054015,2011
  ABSTRACT

  
  

  

• Title	:	Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron
  Journal	:	Phys. Lett. B691 (2010) 238

  
  

  논문

  NUMBER
  AUTHOR	Dong-Won Jung, Pyungwon Ko, Jae Sik Lee, Soo-Hyeon Nam
  TITLE	Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron
  ARCHIVE
  FILE
  JOURNAL	Phys. Lett. B691 (2010) 238
  ABSTRACT

  
  

  

• Title	:	Double quarkonium production at the LHC
  Journal	:	PoS ICHEP2010:220,2010

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jungil Lee, Chaehyun Yu
  TITLE	Double quarkonium production at the LHC
  ARCHIVE
  FILE
  JOURNAL	PoS ICHEP2010:220,2010
  ABSTRACT

  
  

  

• Title	:	Addendum to: Implications of the measurements of $B_s-B_s bar$ mixing on SUSY models
  Journal	:	Phys.Rev.D82:117701,2010

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jae-hyeon Park
  TITLE	Addendum to: Implications of the measurements of $B_s-B_s bar$ mixing on SUSY models
  ARCHIVE	arXiv:1006.5821
  FILE
  JOURNAL	Phys.Rev.D82:117701,2010
  ABSTRACT

  
  

  

• Title	:	Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron
  Journal	:	Phys.Lett.B691:238-242,2010

  
  

  논문

  NUMBER
  AUTHOR	Dong-Won Jung, P. Ko, Jae Sik Lee, Soo-hyeon Nam
  TITLE	Model independent analysis of the forward-backward asymmetry of top quark production at the Tevatron
  ARCHIVE	arXiv:0912.1105
  FILE
  JOURNAL	Phys.Lett.B691:238-242,2010
  ABSTRACT

  
  

  

• Title	:	Electroweak symmetry breaking and cold dark matter from hidden sector strong interaction
  Journal	:	AIP Conf.Proc.1178:37-43,2009

  
  

  논문

  NUMBER
  AUTHOR	Pyungwon Ko
  TITLE	Electroweak symmetry breaking and cold dark matter from hidden sector strong interaction
  ARCHIVE
  FILE
  JOURNAL	AIP Conf.Proc.1178:37-43,2009
  ABSTRACT

  
  

  

• Title	:	Stable Higgs Bosons as Cold Dark Matter
  Journal	:	Phys.Lett.B680:179-183,2009

  
  

  논문

  NUMBER
  AUTHOR	Yutaka Hosotani, Pyungwon Ko, Minoru Tanaka
  TITLE	Stable Higgs Bosons as Cold Dark Matter
  ARCHIVE	arXiv:0908.0212
  FILE
  JOURNAL	Phys.Lett.B680:179-183,2009
  ABSTRACT

  
  

  

• Title	:	Phenomenology of U(1)(L(mu)-L(tau)) charged dark matter at PAMELA and colliders
  Journal	:	JCAP 0910:011,2009

  
  

  논문

  NUMBER
  AUTHOR	Seungwon Baek, Pyungwon Ko
  TITLE	Phenomenology of U(1)(L(mu)-L(tau)) charged dark matter at PAMELA and colliders
  ARCHIVE	arXiv:0811.1646
  FILE
  JOURNAL	JCAP 0910:011,2009
  ABSTRACT

  
  

  

• Title	:	Implications of the measurements of $B_s$ - $bar{B}_s$ mixing on SUSY models
  Journal	:	Phys.Rev.D80:035019,2009

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jae-hyeon Park
  TITLE	Implications of the measurements of $B_s$ - $bar{B}_s$ mixing on SUSY models
  ARCHIVE	arXiv:0809.0705
  FILE
  JOURNAL	Phys.Rev.D80:035019,2009
  ABSTRACT

  
  

  

• Title	:	Supersymmetry and the unification of fundamental interactions
  Journal	:	AIP Conf. Proc. 1078 (2008) 644 p

  
  

  논문

  NUMBER
  AUTHOR	Deog Ki Hong, (ed.), Pyungwon Ko, (ed.)
  TITLE	Supersymmetry and the unification of fundamental interactions
  ARCHIVE
  FILE
  JOURNAL	AIP Conf. Proc. 1078 (2008) 644 p
  ABSTRACT

  
  

  

• Title	:	Sflavor mixing map viewed from a high scale in supersymmetric SU(5)
  Journal	:	JHEP 0811, 051 (2008)

  
  

  논문

  NUMBER
  AUTHOR	Pyungwon Ko, Jae-hyeon Park and Masahiro Yamaguchi
  TITLE	Sflavor mixing map viewed from a high scale in supersymmetric SU(5)
  ARCHIVE	arXiv:0809.2784
  FILE
  JOURNAL	JHEP 0811, 051 (2008)
  ABSTRACT

  
  

  

• Title	:	Holographic QCD beyond the leading order
  Journal	:	JHEP 0806, 094 (2008)

  
  

  논문

  NUMBER
  AUTHOR	Youngman Kim, P. Ko and Xiao-Hong Wu
  TITLE	Holographic QCD beyond the leading order
  ARCHIVE	arXiv:0804.2710
  FILE
  JOURNAL	JHEP 0806, 094 (2008)
  ABSTRACT

  
  

  

• Title	:	Electroweak symmetry breaking and cold dark matter from hidden sector technicolor
  Journal	:	Int. J. Mod. Phys. A23, 3348 (2008)

  
  

  논문

  NUMBER
  AUTHOR	Pyungwon Ko
  TITLE	Electroweak symmetry breaking and cold dark matter from hidden sector technicolor
  ARCHIVE	arXiv:0801.4284
  FILE
  JOURNAL	Int. J. Mod. Phys. A23, 3348 (2008)
  ABSTRACT

  
  

  

• Title	:	Probing nonstandard neutrino physics by two identical detectors with different baselines
  Journal	:	Phys. Rev. D77, 073007 (2008)

  
  

  논문

  NUMBER
  AUTHOR	Nei Cipriano Ribeiro, Hiroshi Nunokawa, Takaaki Kajita, Shoei Nakayama, Pyungwon Ko, and Hisakazu Minakata
  TITLE	Probing nonstandard neutrino physics by two identical detectors with different baselines
  ARCHIVE	arXiv:0712.4314
  FILE
  JOURNAL	Phys. Rev. D77, 073007 (2008)
  ABSTRACT

  
  

  

• Title	:	Neutral scalar Higgs bosons in the USSM at the LHC
  Journal	:	J. Phys. G35, 095007 (2008)

  
  

  논문

  NUMBER
  AUTHOR	S.W.Ham, Taeil Hur, P. Ko and S.K.Oh
  TITLE	Neutral scalar Higgs bosons in the USSM at the LHC
  ARCHIVE	arXiv:0801.2361
  FILE
  JOURNAL	J. Phys. G35, 095007 (2008)
  ABSTRACT

  
  

  

• Title	:	Antisymmetric rank-2 tensor unparticle physics
  Journal	:	Phys. Rev. D76, 096008 (2007)

  
  

  논문

  NUMBER
  AUTHOR	Taeil Hur, P. Ko and Xiao-Hong Wu
  TITLE	Antisymmetric rank-2 tensor unparticle physics
  ARCHIVE	arXiv:0709.0629
  FILE
  JOURNAL	Phys. Rev. D76, 096008 (2007)
  ABSTRACT

  
  

  

• Title	:	String-derived D4 flavor symmetry and phenomenological implications
  Journal	:	Phys. Rev. D76, 035005 (2007)

  
  

  논문

  NUMBER
  AUTHOR	Pyungwon Ko, Tatsuo Kobayashi and Jae-hyeon Park
  TITLE	String-derived D4 flavor symmetry and phenomenological implications
  ARCHIVE	arXiv:0704.2807
  FILE
  JOURNAL	Phys. Rev. D76, 035005 (2007)
  ABSTRACT

  
  

  

• Title	:	Implications of the recent measurement of Bs - Bs mixing on SUSY models
  Journal	:	Nucl. Phys. Proc. Suppl. 163, 185 (2007)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Implications of the recent measurement of Bs - Bs mixing on SUSY models
  ARCHIVE
  FILE
  JOURNAL	Nucl. Phys. Proc. Suppl. 163, 185 (2007)
  ABSTRACT

  
  

  

• Title	:	Partially composite two-Higgs doublet model
  Journal	:	JHEP 0605, 010 (2006)

  
  

  논문

  NUMBER
  AUTHOR	Byungchul Chung, Kang Young Lee, Dong-Won Jung, Pyungwon Ko
  TITLE	Partially composite two-Higgs doublet model
  ARCHIVE	hep-ph/0703223
  FILE
  JOURNAL	JHEP 0605, 010 (2006)
  ABSTRACT

  
  

  

• Title	:	MSSM anatomy of the polarization puzzle in B → ϕK* decays
  Journal	:	Phys. Rev. D73, 034026 (2006)

  
  

  논문

  NUMBER
  AUTHOR	Chao-Shang Huang, Pyungwon Ko, Xiao-Hong Wu, Ya-Dong Yang
  TITLE	MSSM anatomy of the polarization puzzle in B → ϕK* decays
  ARCHIVE	hep-ph/0511129
  FILE
  JOURNAL	Phys. Rev. D73, 034026 (2006)
  ABSTRACT

  
  

  

• Title	:	Bs ! μ+μ- and the upward-going muon flux from the WIMP annihilation in the sun or the earth
  Journal	:	JHEP 0511, 007 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Seungwon Baek, Yeong Gyun Kim and P. Ko
  TITLE	Bs ! μ+μ- and the upward-going muon flux from the WIMP annihilation in the sun or the earth
  ARCHIVE	hep-ph/0506115
  FILE
  JOURNAL	JHEP 0511, 007 (2005)
  ABSTRACT

  
  

  

• Title	:	Direct detection of neutralino dark matter in supergravity
  Journal	:	JHEP 0506, 017 (2005)

  
  

  논문

  NUMBER
  AUTHOR	S. Baek, D.G. Cerdeno, Y.G. Kim, P. Ko and C. Munoz
  TITLE	Direct detection of neutralino dark matter in supergravity
  ARCHIVE	hep-ph/0505019
  FILE
  JOURNAL	JHEP 0506, 017 (2005)
  ABSTRACT

  
  

  

• Title	:	Re (ϵ′/ϵK ) vs. Bd → ϕKS CP asymmetry
  Journal	:	Phys. Rev. D72, 016004 (2005)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jae-hyeon Park and A. Masiero
  TITLE	Re (ϵ′/ϵK ) vs. Bd → ϕKS CP asymmetry
  ARCHIVE	hep-ph/0503102
  FILE
  JOURNAL	Phys. Rev. D72, 016004 (2005)
  ABSTRACT

  
  

  

• Title	:	Lepton masses and mixing angles from heterotic orbifold models
  Journal	:	Phys. Rev. D71, 095010 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Pyungwon Ko, Tatsuo Kobayashi and Jae-hyeon Park
  TITLE	Lepton masses and mixing angles from heterotic orbifold models
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D71, 095010 (2005)
  ABSTRACT

  
  

  

• Title	:	Color-evaporation-model calculation of e+e- → J/ψ + cc + X at s = 10.6 GeV
  Journal	:	Phys. Rev. D71, 094019 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Daekyoung Kang, Jong-Wan Lee, Jungil Lee, Taewon Kim and Pyungwon Ko
  TITLE	Color-evaporation-model calculation of e+e- → J/ψ + cc + X at s = 10.6 GeV
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D71, 094019 (2005)
  ABSTRACT

  
  

  

• Title	:	Inclusive production of four charm hadrons in e+e- annihilation at B factories
  Journal	:	Phys. Rev. D71, 071501 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Daekyoung Kang, Jong-Wan Lee, Jungil Lee, Taewon Kim and Pyungwon Ko
  TITLE	Inclusive production of four charm hadrons in e+e- annihilation at B factories
  ARCHIVE	hep-ph/0412224
  FILE
  JOURNAL	Phys. Rev. D71, 071501 (2005)
  ABSTRACT

  
  

  

• Title	:	Neutralino dark matter scattering and Bs → μ+μ- in SUSY models
  Journal	:	JHEP 0502, 067 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Seungwon Baek, Yeong Gyun Kim and P. Ko
  TITLE	Neutralino dark matter scattering and Bs → μ+μ- in SUSY models
  ARCHIVE	hep-ph/0406033
  FILE
  JOURNAL	JHEP 0502, 067 (2005)
  ABSTRACT

  
  

  

• Title	:	Dipion invariant mass spectrum in X(3872) → J/ψππ
  Journal	:	Phys. Rev. D71, 034025 (2005); Erratum-ibid. D71, 099902 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Taewon Kim and P. Ko
  TITLE	Dipion invariant mass spectrum in X(3872) → J/ψππ
  ARCHIVE	hep-ph/0405265
  FILE
  JOURNAL	Phys. Rev. D71, 034025 (2005); Erratum-ibid. D71, 099902 (2005)
  ABSTRACT

  
  

  

• Title	:	Chiral perturbation theory for pentaquark baryons and its applications
  Journal	:	Phys.Lett.B611, 87 (2005)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jungil Lee, Taekoon Lee and Jae-hyeon Park
  TITLE	Chiral perturbation theory for pentaquark baryons and its applications
  ARCHIVE	hep-ph/0312147
  FILE
  JOURNAL	Phys.Lett.B611, 87 (2005)
  ABSTRACT

  
  

  

• Title	:	Bd → ϕKS and supersymmetry
  Journal	:	Phys. Rev. D70, 035015 (2004)

  
  

  논문

  NUMBER
  AUTHOR	G.L. Kane, P. Ko, Hai-bin Wang, C. Kolda, Jae-hyeon Park and Lian-Tao Wang
  TITLE	Bd → ϕKS and supersymmetry
  ARCHIVE	hep-ph/0212092
  FILE
  JOURNAL	Phys. Rev. D70, 035015 (2004)
  ABSTRACT

  
  

  

• Title	:	Quark masses and mixing angles in heterotic orbifold models
  Journal	:	Phys. Lett. B598, 263 (2004)

  
  

  논문

  NUMBER
  AUTHOR	Pyungwon Ko, Tatsuo Kobayashi and Jae-hyeon Park
  TITLE	Quark masses and mixing angles in heterotic orbifold models
  ARCHIVE	hep-ph/0406041
  FILE
  JOURNAL	Phys. Lett. B598, 263 (2004)
  ABSTRACT

  
  

  

• Title	:	Bd → ϕKS CP asymmetries as an important probe of supersymmetry
  Journal	:	Phys. Rev. Lett. 90 141803 (2003)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, G.L. Kane, P. Ko, Hai-bin Wang, C. Kolda, Jae-hyeon Park, Lian-Tao Wang
  TITLE	Bd → ϕKS CP asymmetries as an important probe of supersymmetry
  ARCHIVE	hep-ph/0304239
  FILE
  JOURNAL	Phys. Rev. Lett. 90 141803 (2003)
  ABSTRACT

  
  

  

• Title	:	SUSY breaking mediation mechanisms and (g - 2)μ, B → Xsγ, B → Xsl+l- and Bs → μ+μ-
  Journal	:	JHEP 0303, 054 (2003)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Seung-won Baek and Wan Young Song
  TITLE	SUSY breaking mediation mechanisms and (g - 2)μ, B → Xsγ, B → Xsl+l- and Bs → μ+μ-
  ARCHIVE	hep-ph/0208112
  FILE
  JOURNAL	JHEP 0303, 054 (2003)
  ABSTRACT

  
  

  

• Title	:	CP violations in the K and B meson systems in the SUSY models with (S3)3 flavor summetry
  Journal	:	JHEP 0209, 017 (2002)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jae-hyeon Park
  TITLE	CP violations in the K and B meson systems in the SUSY models with (S3)3 flavor summetry
  ARCHIVE	hep-ph/0207016
  FILE
  JOURNAL	JHEP 0209, 017 (2002)
  ABSTRACT

  
  

  

• Title	:	Is large SUSY CP violation compatible with the current data?
  Journal	:	J. Korean Phys. Soc. 41, 27 (2002)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, P. Ko and Jae-hyeon Park
  TITLE	Is large SUSY CP violation compatible with the current data?
  ARCHIVE
  FILE
  JOURNAL	J. Korean Phys. Soc. 41, 27 (2002)
  ABSTRACT

  
  

  

• Title	:	Implications on SUSY breaking mediations mechanisms from observing Bs → μ+μ- and the muon (g - 2)
  Journal	:	Phys. Rev. Lett.89, 271801 (2002)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Seung-won Baek and Wan Young Song
  TITLE	Implications on SUSY breaking mediations mechanisms from observing Bs → μ+μ- and the muon (g - 2)
  ARCHIVE	hep-ph/0205259
  FILE
  JOURNAL	Phys. Rev. Lett.89, 271801 (2002)
  ABSTRACT

  
  

  

• Title	:	B0 - B0 mixing, B → J/ψKs and B → Xd γ in general MSSM
  Journal	:	Eur. Phys. J.C25, 615 (2002)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jaehyeon Park and G. Kramer
  TITLE	B0 - B0 mixing, B → J/ψKs and B → Xd γ in general MSSM
  ARCHIVE	hep-ph/0206297
  FILE
  JOURNAL	Eur. Phys. J.C25, 615 (2002)
  ABSTRACT

  
  

  

• Title	:	CP violating chargino contributions to the Higgs coupling to photon pairs in the decoupling regime of Higgs sector
  Journal	:	Phys. Rev. D 66, 016009 (2002)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S.Y. Choi, Byung-chul Chung and Jae Sik Lee
  TITLE	CP violating chargino contributions to the Higgs coupling to photon pairs in the decoupling regime of Higgs sector
  ARCHIVE	hep-ph/0206025
  FILE
  JOURNAL	Phys. Rev. D 66, 016009 (2002)
  ABSTRACT

  
  

  

• Title	:	Muon anomalous magnetic moment from effective supersymmetry
  Journal	:	Eur. Phys. J. C 24, 613-618 (2002)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S. Baek and Jae-hyeon Park
  TITLE	Muon anomalous magnetic moment from effective supersymmetry
  ARCHIVE	hep-ph/0203251
  FILE
  JOURNAL	Eur. Phys. J. C 24, 613-618 (2002)
  ABSTRACT

  
  

  

• Title	:	Muon anomalous magnetic moment, B → Xsγ and dark matter detection in the string models with dilaton domination
  Journal	:	Phys. Rev. D65, 035004 (2002)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S. Baek and Hong Seok Lee
  TITLE	Muon anomalous magnetic moment, B → Xsγ and dark matter detection in the string models with dilaton domination
  ARCHIVE	hep-ph/0103218
  FILE
  JOURNAL	Phys. Rev. D65, 035004 (2002)
  ABSTRACT

  
  

  

• Title	:	Muon anomalous g - 2 and gauged Lɥ - Lτ models
  Journal	:	Phys. Rev. D 64, 055006 (2001)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S. Baek, N.G. Deshpande and X.G. He
  TITLE	Muon anomalous g - 2 and gauged Lɥ - Lτ models
  ARCHIVE	hep-ph/0104141
  FILE
  JOURNAL	Phys. Rev. D 64, 055006 (2001)
  ABSTRACT

  
  

  

• Title	:	Gluino squark contributions to CP violations in the kaon system
  Journal	:	Nucl. Phys. B 609, 442-468 (2001)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S. Baek, J.H. Jang and J.H. Park
  TITLE	Gluino squark contributions to CP violations in the kaon system
  ARCHIVE	hep-ph/0105028
  FILE
  JOURNAL	Nucl. Phys. B 609, 442-468 (2001)
  ABSTRACT

  
  

  

• Title	:	Phenomenology of the radion in the Randall-Sundrum scenario at colliders
  Journal	:	Phys. Lett. B 487, 299-305 (2000)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Sae Byok Bae, Hong Seok Lee, Jungil Lee
  TITLE	Phenomenology of the radion in the Randall-Sundrum scenario at colliders
  ARCHIVE	hep-ph/0002224
  FILE
  JOURNAL	Phys. Lett. B 487, 299-305 (2000)
  ABSTRACT

  
  

  

• Title	:	Fully supersymmetric CP violations in the kaon system
  Journal	:	Phys. Rev. D 62, 117701 (2000)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S. Baek, J.H. Jang and J.H. Park
  TITLE	Fully supersymmetric CP violations in the kaon system
  ARCHIVE	hep-ph/9907572
  FILE
  JOURNAL	Phys. Rev. D 62, 117701 (2000)
  ABSTRACT

  
  

  

• Title	:	Effects of supersymmetric CP violating phases in B → Xs l+l- and ϵK
  Journal	:	Phys. Lett. B 462, 95-102 (1999)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S. Baek
  TITLE	Effects of supersymmetric CP violating phases in B → Xs l+l- and ϵK
  ARCHIVE	hep-ph/9904283
  FILE
  JOURNAL	Phys. Lett. B 462, 95-102 (1999)
  ABSTRACT

  
  

  

• Title	:	Probing SUSY induced CP violations at B factories
  Journal	:	Phys. Rev. Lett. 83, 488-491 (1999)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S. Baek
  TITLE	Probing SUSY induced CP violations at B factories
  ARCHIVE	hep-ph/9812229
  FILE
  JOURNAL	Phys. Rev. Lett. 83, 488-491 (1999)
  ABSTRACT

  
  

  

• Title	:	Complete analysis of photino mediated lepton flavor violations in generalized supersymmetric models
  Journal	:	Phys. Rev. D 59, 055018 (1999)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Y.-G. Kim. J. S. Lee and K. Y. Lee
  TITLE	Complete analysis of photino mediated lepton flavor violations in generalized supersymmetric models
  ARCHIVE	hep-ph/9811211
  FILE
  JOURNAL	Phys. Rev. D 59, 055018 (1999)
  ABSTRACT

  
  

  

• Title	:	B decays into two light pseudoscalar mesons and possible effects of enhanced b → sg
  Journal	:	Phys.Rev.D 59, 034025 (1999)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, J.-H. Jang, Y.G. Kim
  TITLE	B decays into two light pseudoscalar mesons and possible effects of enhanced b → sg
  ARCHIVE	hep-ph/9810366
  FILE
  JOURNAL	Phys.Rev.D 59, 034025 (1999)
  ABSTRACT

  
  

  

• Title	:	Possible new physics signals in B → Xsγ and B → Xsl+l-
  Journal	:	Nucl. Phys.B 544, 64-88 (1999)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Y.G. Kim and J.S. Lee
  TITLE	Possible new physics signals in B → Xsγ and B → Xsl+l-
  ARCHIVE	hep-ph/9810336
  FILE
  JOURNAL	Nucl. Phys.B 544, 64-88 (1999)
  ABSTRACT

  
  

  

• Title	:	Testing J/ψ production mechanisms in B → J/ψ + X
  Journal	:	J. Kor. Phys. Soc. 34, 301 (1999)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jungil Lee and H.S. Song
  TITLE	Testing J/ψ production mechanisms in B → J/ψ + X
  ARCHIVE
  FILE
  JOURNAL	J. Kor. Phys. Soc. 34, 301 (1999)
  ABSTRACT

  
  

  

• Title	:	A new method for extracting the weak phase γ from B → DK(*) decays
  Journal	:	Phys. Rev. D 58, 111302 (1998) (Rapid Communications)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, J.-H. Jang
  TITLE	A new method for extracting the weak phase γ from B → DK(*) decays
  ARCHIVE	hep-ph/9807496
  FILE
  JOURNAL	Phys. Rev. D 58, 111302 (1998) (Rapid Communications)
  ABSTRACT

  
  

  

• Title	:	Mass matrix ansatz for degenerate neutrinos consistent with solar and atmospheric neutrino data
  Journal	:	Phys. Lett. B 442, 249-254 (1998)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, K. Kang, S.K. Kang, J.E. Kim
  TITLE	Mass matrix ansatz for degenerate neutrinos consistent with solar and atmospheric neutrino data
  ARCHIVE
  FILE
  JOURNAL	Phys. Lett. B 442, 249-254 (1998)
  ABSTRACT

  
  

  

• Title	:	Polarized J/ψ production at CLEO
  Journal	:	J. Kor. Phys. Soc. 33, 97 (1998)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S. Baek, J. Lee and H.S. Song
  TITLE	Polarized J/ψ production at CLEO
  ARCHIVE	hep-ph/9804455
  FILE
  JOURNAL	J. Kor. Phys. Soc. 33, 97 (1998)
  ABSTRACT

  
  

  

• Title	:	Contribution of b → sgg through the QCD anomaly in exclusive decays B± → (η′ , η)(K±,K*±) and B0 → (η′ , η)(K0,K0)
  Journal	:	Phys. Lett.B 424, 161-174 (1998)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, A. Ali, J. Chay and C. Greub
  TITLE	Contribution of b → sgg through the QCD anomaly in exclusive decays B± → (η′ , η)(K±,K*±) and B0 → (η′ , η)(K0,K0)
  ARCHIVE	hep-ph/9810300
  FILE
  JOURNAL	Phys. Lett.B 424, 161-174 (1998)
  ABSTRACT

  
  

  

• Title	:	Supersymmetric interpretation of high-Q2 HERA events and other related topics
  Journal	:	Phys. Rev. D 57, 489-495 (1998)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jihn E. Kim
  TITLE	Supersymmetric interpretation of high-Q2 HERA events and other related topics
  ARCHIVE	hep-ph/9706387
  FILE
  JOURNAL	Phys. Rev. D 57, 489-495 (1998)
  ABSTRACT

  
  

  

• Title	:	Almost mally broken permutation symmetry for neutrino mass matrix
  Journal	:	Mod. Phys. Lett. A 12, 1175-1184 (1997)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Kyungsik Kang, Sinkyu Kang and Jihn E Kim
  TITLE	Almost mally broken permutation symmetry for neutrino mass matrix
  ARCHIVE	hep-ph/9611369
  FILE
  JOURNAL	Mod. Phys. Lett. A 12, 1175-1184 (1997)
  ABSTRACT

  
  

  

• Title	:	More on R parity and lepton family number violating coupling from muon(ium) conversion, and tau and π0 decays
  Journal	:	Phys. Rev. D 56, 100-106 (1997)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jihn E. Kim and Dae-Gyu Lee
  TITLE	More on R parity and lepton family number violating coupling from muon(ium) conversion, and tau and π0 decays
  ARCHIVE	hep-ph/9701381
  FILE
  JOURNAL	Phys. Rev. D 56, 100-106 (1997)
  ABSTRACT

  
  

  

• Title	:	Color-octet mechanism and J/ψ polarization at LEP
  Journal	:	Phys. Rev. D 55, 6839-6843 (1997)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Seungwon Baek, Jungil Lee, and H.S. Song
  TITLE	Color-octet mechanism and J/ψ polarization at LEP
  ARCHIVE	hep-ph/9701208
  FILE
  JOURNAL	Phys. Rev. D 55, 6839-6843 (1997)
  ABSTRACT

  
  

  

• Title	:	Color-octet mechanism in the inclusive D wave charmonium productionsin B decays
  Journal	:	Phys. Lett. B 395, 107-112 (1997)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jungil Lee and H.S. Song
  TITLE	Color-octet mechanism in the inclusive D wave charmonium productionsin B decays
  ARCHIVE	hep-ph/9701235
  FILE
  JOURNAL	Phys. Lett. B 395, 107-112 (1997)
  ABSTRACT

  
  

  

• Title	:	Color-octet heavy quarkonium productions in Z0 decays at LEP
  Journal	:	Phys. Lett. B 389, 609-615 (1996)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Seungwon Baek, Jungil Lee and H.S. Song
  TITLE	Color-octet heavy quarkonium productions in Z0 decays at LEP
  ARCHIVE	hep-ph/9607236
  FILE
  JOURNAL	Phys. Lett. B 389, 609-615 (1996)
  ABSTRACT

  
  

  

• Title	:	Color-octet mechanism in γ + p → J/ψ +X
  Journal	:	Phys. Rev. D 53, 4312-4325 (1996)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jungil Lee and H.S. Song
  TITLE	Color-octet mechanism in γ + p → J/ψ +X
  ARCHIVE	hep-ph/9602223
  FILE
  JOURNAL	Phys. Rev. D 53, 4312-4325 (1996)
  ABSTRACT

  
  

  

• Title	:	A simple modification of the maximal mixing scenario for three light neutrinos
  Journal	:	Z. Phys. C 72, 671-675 (1996)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Kyungsik Kang and Jihn E. Kim
  TITLE	A simple modification of the maximal mixing scenario for three light neutrinos
  ARCHIVE	hep-ph/9503436
  FILE
  JOURNAL	Z. Phys. C 72, 671-675 (1996)
  ABSTRACT

  
  

  

• Title	:	a1 (1260) contributions to photon and dilepton productions from hot hadronic matter : revisited
  Journal	:	Phys. Rev. D 53, 4787-4792 (1996)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, J.K. Kim, K.Y. Lee and S. Rudaz
  TITLE	a1 (1260) contributions to photon and dilepton productions from hot hadronic matter : revisited
  ARCHIVE	hep-ph/9602293
  FILE
  JOURNAL	Phys. Rev. D 53, 4787-4792 (1996)
  ABSTRACT

  
  

  

• Title	:	Chiral perturbation theory vs. vector meson dominance in the decays ϕ → ργγ and ϕ → ωγγ
  Journal	:	Phys. Lett. B 366, 287-292 (1996)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jungil Lee and H.S. Song
  TITLE	Chiral perturbation theory vs. vector meson dominance in the decays ϕ → ργγ and ϕ → ωγγ
  ARCHIVE	hep-ph/9510205
  FILE
  JOURNAL	Phys. Lett. B 366, 287-292 (1996)
  ABSTRACT

  
  

  

• Title	:	Inclusive S-wave charmonium productions in B decays
  Journal	:	Phys. Rev. D 53, 1409-1415 (1996)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Jungil Lee and H.S. Song
  TITLE	Inclusive S-wave charmonium productions in B decays
  ARCHIVE	hep-ph/9510202
  FILE
  JOURNAL	Phys. Rev. D 53, 1409-1415 (1996)
  ABSTRACT

  
  

  

• Title	:	Estimates of χc(2P) production rates in B and r(1S) decays
  Journal	:	Phys. Rev. D 52, 3108-3110 (1995)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Estimates of χc(2P) production rates in B and r(1S) decays
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 52, 3108-3110 (1995)
  ABSTRACT

  
  

  

• Title	:	Search for η′c and hc(1P1) states in the e+e- annihilations
  Journal	:	Phys. Rev. D 52, 1710-1712 (1995)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Search for η′c and hc(1P1) states in the e+e- annihilations
  ARCHIVE	hep-ph/9505299
  FILE
  JOURNAL	Phys. Rev. D 52, 1710-1712 (1995)
  ABSTRACT

  
  

  

• Title	:	KLe5 decay as a background to KL → π0μ±e∓
  Journal	:	Phys. Rev. D 51, 3455-3458 (1995)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, K.Y. Lee and J.K. Kim
  TITLE	KLe5 decay as a background to KL → π0μ±e∓
  ARCHIVE	hep-ph/9502320
  FILE
  JOURNAL	Phys. Rev. D 51, 3455-3458 (1995)
  ABSTRACT

  
  

  

• Title	:	η → π0γγ and γγ → π0π0 in O(p6) chiral perturbation theory
  Journal	:	Phys. Lett. B 349, 555-560 (1995)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	η → π0γγ and γγ → π0π0 in O(p6) chiral perturbation theory
  ARCHIVE	hep-ph/9503253
  FILE
  JOURNAL	Phys. Lett. B 349, 555-560 (1995)
  ABSTRACT

  
  

  

• Title	:	New approach for measuring |Vbu| at future B-factories
  Journal	:	Phys. Rev. D 50, 5762-5766 (1994)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, C.S. Kim, D.S. Hwang and W. Namgung
  TITLE	New approach for measuring |Vbu| at future B-factories
  ARCHIVE	hep-ph/9406251
  FILE
  JOURNAL	Phys. Rev. D 50, 5762-5766 (1994)
  ABSTRACT

  
  

  

• Title	:	Final state ππ interactions in r(3S) → r(1S) ππ
  Journal	:	Phys. Rev. D 50, 389-394 (1994)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S.Chakravarty and S.M. Kim
  TITLE	Final state ππ interactions in r(3S) → r(1S) ππ
  ARCHIVE	hep-ph/9310376
  FILE
  JOURNAL	Phys. Rev. D 50, 389-394 (1994)
  ABSTRACT

  
  

  

• Title	:	Phenomenology of scalar and vector mesons in the linear sigma model
  Journal	:	Phys. Rev. D 50, 6877-6894 (1994)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Serge Rudaz
  TITLE	Phenomenology of scalar and vector mesons in the linear sigma model
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 50, 6877-6894 (1994)
  ABSTRACT

  
  

  

• Title	:	Testing the SU(3)L × U(1)X model from muonium → antimuonium conversion
  Journal	:	Il Nuovo Cimento 107 A, 809-811 (1994)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Testing the SU(3)L × U(1)X model from muonium → antimuonium conversion
  ARCHIVE
  FILE
  JOURNAL	Il Nuovo Cimento 107 A, 809-811 (1994)
  ABSTRACT

  
  

  

• Title	:	Schrodinger fields on the plane with [U(1)]N Chern-Simons interactions and Generalized self-dual solitons
  Journal	:	Phys. Rev. D 48, 1821-1840 (1993)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, Changju Kim, Choonkyu Lee, Bum-Hoon Lee and Hyunsoo Min
  TITLE	Schrodinger fields on the plane with [U(1)]N Chern-Simons interactions and Generalized self-dual solitons
  ARCHIVE	hep-th/9303131
  FILE
  JOURNAL	Phys. Rev. D 48, 1821-1840 (1993)
  ABSTRACT

  
  

  

• Title	:	Is Upsilon (3S) a pure S-wave ?
  Journal	:	Phys. Rev. D 48, 1212-1219 (1993)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S. Chakravarty and S.M. Kim
  TITLE	Is Upsilon (3S) a pure S-wave ?
  ARCHIVE	hep-ph/9301249
  FILE
  JOURNAL	Phys. Rev. D 48, 1212-1219 (1993)
  ABSTRACT

  
  

  

• Title	:	Radiative and hadronic decays of the charmonium 1P1(cc) state
  Journal	:	Phys. Rev. D 47, 2837-2839 (1993)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Radiative and hadronic decays of the charmonium 1P1(cc) state
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 47, 2837-2839 (1993)
  ABSTRACT

  
  

  

• Title	:	ππ spectrum in r(3S) → r(1S)ππ
  Journal	:	Phys. Rev. D 48, 1205-1211 (1993)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, S. Chakravarty
  TITLE	ππ spectrum in r(3S) → r(1S)ππ
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 48, 1205-1211 (1993)
  ABSTRACT

  
  

  

• Title	:	Contributions of the C-odd axial vector resonances to η → π0γγ and γγ → π0π0
  Journal	:	Phys. Rev. D 47, 3933-3937 (1993)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Contributions of the C-odd axial vector resonances to η → π0γγ and γγ → π0π0
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 47, 3933-3937 (1993)
  ABSTRACT

  
  

  

• Title	:	Isospin symmetry breaking S-wave ππ form factor in KL → π0π∓e±(ν)
  Journal	:	Phys. Rev. D 47, 1250-1251 (1993)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Isospin symmetry breaking S-wave ππ form factor in KL → π0π∓e±(ν)
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 47, 1250-1251 (1993)
  ABSTRACT

  
  

  

• Title	:	Branching ratio of r(1D) → r(1S)ππ
  Journal	:	Phys. Rev. D 47, 208-209 (1993)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Branching ratio of r(1D) → r(1S)ππ
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 47, 208-209 (1993)
  ABSTRACT

  
  

  

• Title	:	Chiral loop contribution to D → K*lν
  Journal	:	Phys. Rev. D 47, 1964{1972 (1993)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Chiral loop contribution to D → K*lν
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 47, 1964{1972 (1993)
  ABSTRACT

  
  

  

• Title	:	KL → π0π∓e±(ν) and vector symmetry
  Journal	:	Phys. Rev. D 46, 3813{3816 (1992)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	KL → π0π∓e±(ν) and vector symmetry
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 46, 3813{3816 (1992)
  ABSTRACT

  
  

  

• Title	:	KL → μ+μ- and related topics
  Journal	:	Phys. Rev.D 45, 174-177 (1992)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	KL → μ+μ- and related topics
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev.D 45, 174-177 (1992)
  ABSTRACT

  
  

  

• Title	:	Role of vector mesons in rare kaon decays
  Journal	:	Phys. Rev. D 44, 139-165 (1991)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Role of vector mesons in rare kaon decays
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 44, 139-165 (1991)
  ABSTRACT

  
  

  

• Title	:	KL → 2γ and KL → π+π-γ decays
  Journal	:	Phys. Rev.D 43, R4-8 (1991)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, T.N. Truong
  TITLE	KL → 2γ and KL → π+π-γ decays
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev.D 43, R4-8 (1991)
  ABSTRACT

  
  

  

• Title	:	Analysis of 2γ and π+π-γ decays of η and η′ using chiral anomalies
  Journal	:	Phys. Rev. D 42, 2419-2422 (1990)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, T.N. Truong
  TITLE	Analysis of 2γ and π+π-γ decays of η and η′ using chiral anomalies
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 42, 2419-2422 (1990)
  ABSTRACT

  
  

  

• Title	:	Vector-meson contributions to the processes γγ → π0π0, π+π-,KL → π0γγ and K+ → π+γγ
  Journal	:	Phys. Rev. D 41, 1531-1540 (1990)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko
  TITLE	Vector-meson contributions to the processes γγ → π0π0, π+π-,KL → π0γγ and K+ → π+γγ
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 41, 1531-1540 (1990)
  ABSTRACT

  
  

  

• Title	:	Pion-pair contribution to the decay KL → π0γγ
  Journal	:	Phys. Rev. D 40, 3775-3778 (1989)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, J.L. Rosner
  TITLE	Pion-pair contribution to the decay KL → π0γγ
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 40, 3775-3778 (1989)
  ABSTRACT

  
  

  

• Title	:	Two-loop renormalization of the Pontryagin density in the pure Yang-Mills theory
  Journal	:	Phys. Rev. D 36, 1943{1946 (1987)

  
  

  논문

  NUMBER
  AUTHOR	P. Ko, T. Lee
  TITLE	Two-loop renormalization of the Pontryagin density in the pure Yang-Mills theory
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. D 36, 1943{1946 (1987)
  ABSTRACT

  
  

  

• Title	:	Topologically nontrivial configurations in certain field theories
  Journal	:	Seoul National University (1985) (unpublished)

  
  

  논문

  NUMBER
  AUTHOR	M.S. Thesis
  TITLE	Topologically nontrivial configurations in certain field theories
  ARCHIVE
  FILE
  JOURNAL	Seoul National University (1985) (unpublished)
  ABSTRACT