336 citations · 1.3k across the 34 of their papers we have counts for
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Higgs potential and hidden light Higgs scenario in two Higgs doublet models
Sanghyeon Chang, Sin Kyu Kang, Jong-Phil Lee +1
In two Higgs doublet models (2HDM), there exists an interesting possibility, the hidden light Higgs scenario, that the discovered SM-like Higgs boson is the heavier \textit{CP}-eve…
Two Higgs doublet models for the LHC Higgs boson data at 7 and 8 TeV
Sanghyeon Chang, Sin Kyu Kang, Jong-Phil Lee +3
Updated LHC data on the new 126 GeV boson during the 7 and 8 TeV runnings strengthen the standard model Higgs boson interpretation further. Through the global analysis, we in…
Comprehensive study of two Higgs doublet model in light of the new boson with mass around 125 GeV
Sanghyeon Chang, Sin Kyu Kang, Jong-Phil Lee +3
The recent discovery of a new boson of mass roughly 125 GeV has been reported by the ATLAS and CMS collaborations. Although its signals in various decay modes resemble those of the…
Direct bound on the minimal Universal Extra Dimension model from the resonance search at the Tevatron
Sanghyeon Chang, Kang Young Lee, So Young Shim +1
In the minimal Universal Extra Dimension (mUED) model, the second Kaluza-Klein (KK) gluon has loop-induced vertices with the standard model quarks, mediated by the first…
Implications on the mUED model from the early LHC data on $\ell+\met$ signal
Sanghyeon Chang, Kang Young Lee, Jeonghyeon Song
Recently the ATLAS and CMS collaborations reported their search for a new heavy gauge boson with one lepton plus missing transverse momentum. We find that , the secon…
Probing axino LSP from diphotons events with large missing transverse energy
Sanghyeon Chang, Kang Young Lee, Jeonghyeon Song
In a supersymmetry model with an axino as the lightest supersymmetric particle (LSP) and a Bino as the next LSP (NLSP), supersymmetry particles produced in pair at a high energy co…
The CDF dijet excess and Z'_{cs} coupled to the second generation quarks
Sanghyeon Chang, Kang Young Lee, Jeonghyeon Song
Recently the CDF collaboration has reported the excess in the dijet invariant-mass distribution of the Wjj events, corresponding to a significance of 3.2 standard deviations. Consi…
The second Kaluza-Klein neutral Higgs bosons in the minimal Universal Extra Dimension model
Sanghyeon Chang, Kang Young Lee, Jeonghyeon Song
Loop-induced decay of a neutral Higgs boson into a pair of gluons or photons has great implications for the Higgs discovery at the LHC. If the Higgs boson is heavy with mass above…
The B ---> π K puzzle and the Bulk Randall-Sundurm model
Sanghyeon Chang, C. S. Kim, Jeonghyeon Song
The recent measurements of the direct CP asymmetries () in the penguin-dominated decays show some discrepancy from the standard model (SM) prediction. While $A_{…
Custodial bulk Randall-Sundrum model and B->K* l+ l'-
Sanghyeon Chang, C. S. Kim, Jeonghyeon Song
The custodial Randall-Sundrum model based on SU(2)_L X SU(2)_R X U(1)_(B-L) generates new flavor-changing-neutral-current (FCNC) phenomena at tree level, mediated by Kaluza-Klein n…
Constraint of B_{d,s}-bar{B}_{d,s} mixing on warped extra-dimension model
Sanghyeon Chang, C. S. Kim, Jeonghyeon Song
Recent CDF measurement of the Bs-Bs oscillation frequency, at the Tevatron imposes significant constraint on various models for new physics. A warped extra-dimension model with cus…
Hierarchical Mass Structure of Fermions in Warped Extra Dimension
Sanghyeon Chang, C. S. Kim, Masahiro Yamaguchi
The warped bulk standard model has been studied in the Randall-Sundrum background on interval with the bulk gauge symmetry $SU(3)\times SU(2)_L\times SU(2)_R\time…
Kaluza-Klein masses of bulk fields with general boundary conditions in AdS
Sanghyeon Chang, Seong Chan Park, Jeonghyeon Song
Recently bulk Randall-Sundrum theories with the gauge group have drawn a lot of interest as an alternative to electroweak symmetry breaki…
Minimal seesaw model with tri/bi-maximal mixing and leptogenesis
Sanghyeon Chang, Sin Kyu Kang, Kim Siyeon
We examine minimal seesaw mechanism in which the masses of light neutrinos are described with tri/bi-maximal mixing in the basis where the charged-lepton Yukawa matrix and heavy Ma…
Renormalization Invariants of the Neutrino Mass Matrix
Sanghyeon Chang, T. K. Kuo
The renormalization evolution of all parameters in the neutrino mass matrix depends only on one variable, the energy scale. This fact, coupled with rephasing considerations, leads…
Axion Radiation from Strings
C. Hagmann, S. Chang, P. Sikivie
This paper revisits the problem of the string decay contribution to the axion cosmological energy density. We show that this contribution is proportional to the average relative in…
Bulk Standard Model in the Randall-Sundrum Background
Sanghyeon Chang, Junji Hisano, Hiroaki Nakano +2
We discuss issues in an attempt to put the Standard Model (SM) in five-dimensional anti-de Sitter spacetime compactified on . The recently-proposed approach to the gauge h…
Fate of Gravitons in Warped Extra Dimension
Sanghyeon Chang, Masahiro Yamaguchi
Interaction of bulk gravitons to Standard Model particles is examined in the scenario of warped extra dimension. It is found that the length of the extra dimension is of physical i…
Axion in large extra dimension
Sanghyeon Chang, Shiro Tazawa, Masahiro Yamaguchi
We examine the axion model in the large extra dimensions scenario with TeV scale gravity. To obtain an intermediate-scale decay constant of the axion, the axion is assumed to live…
Axion model in extra dimensions with TeV scale gravity
Sanghyeon Chang, Shiro Tazawa, Masahiro Yamaguchi
A simple axion model is proposed in the scenario of large extra dimensions where gravity scale is as low as 1 TeV. To obtain an intermediate-scale decay constant of the axion, the…
Axions from wall decay
S. Chang, C. Hagmann, P. Sikivie
We discuss the decay of axion walls bounded by strings and present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale…
Axions from string decay
C. Hagmann, S. Chang, P. Sikivie
We have studied numerically the evolution and decay of axion strings. These global defects decay mainly by axion emission and thus contribute to the cosmological axion density. The…
Studies of the motion and decay of axion walls bounded by strings
S. Chang, C. Hagmann, P. Sikivie
We discuss the appearance at the QCD phase transition, and the subsequent decay, of axion walls bounded by strings in N=1 axion models. We argue on intuitive grounds that the main…
Drell-Yan Non-Singlet Spin Cross Sections and Spin Asymmetry to (II)
Sanghyeon Chang, Claudio Coriano, R. D. Field
We present predictions for the non-singlet Drell-Yan longitudinal spin cross sections and spin asymmetry, , in proton-proton collisions at large at the RHIC energy of…