Related papers: The Z2 Two Higgs Doublet Model and the hierarchy p…
The existence of supersymmetry above a few TeV and that of two Higgs doublets at the electroweak energy scale do not necessarily result in the minimal supersymmetric standard model (MSSM). An interesting counter example is given with m_h <…
We consider the conditions for the validity of a two-Higgs doublet model at high energy scales, together with all other low- and high-energy constraints. The constraints on the parameter space at low energy, including the measured value of…
Recent reports from the Large Hadron Collider indicate two excesses: one in the lighter Higgs mass region around 95 GeV, and another in the rare $Z \gamma$ final state of the Standard Model (SM) 125 GeV Higgs decay. These anomalies are…
After the discovery of a Standard Model-like boson with mass of about 125 GeV the possibility of an enlarged scalar sector arises naturally. Here we present the current status of the phenomenology of the two-Higgs-doublet models with a…
We analyze a model for the Higgs sector with two scalar doublets and a $Z_2$ symmetry that is manifest in the Yukawa sector but broken in the potential. Thus, one of the doublets breaks the electroweak symmetry and has tree-level Yukawa…
We study the process q q, g g -> A -> Z* h in a 2-Higgs Doublet Model Type-II where the mass of the CP-odd Higgs state A is lower than the rest mass of the Z and h particles (the latter being the Standard Model-like Higgs state), i.e., mA <…
It is generally believed that the low energy effective theory of the minimal supersymmetric standard model is the type 2 two Higgs doublet model. We will show that the type 1 two Higgs doublet model can also as the effective of…
Since the current LHC Higgs data suggest the couplings of the observed 125 GeV Higgs boson to be close to the Standard Model (SM) expectations, any extended Higgs sector must lead to the so-called SM alignment limit, where one of the Higgs…
The confirmation of the Higgs boson in Run I data at the Large Hadron Collider (LHC) and the excesses in recent Run II data suggest scenarios beyond the Standard Model (SM). We pursue a study in a minimal model which is an extension of a…
The goal of this report is to summarize the current situation and discuss possible search strategies for charged scalars, in non-supersymmetric extensions of the Standard Model at the LHC. Such scalars appear in Multi-Higgs-Doublet models…
The stringent constraints from the direct searches for exotic scalars at the LHC as well as indirect bounds from flavor physics measurements have imposed severe restrictions on the parameter space of new physics models featuring extended…
We report on an attempt to solve the gauge hierarchy problem in the framework of higher dimensional gauge theories. Both classical Higgs mass and quadratically divergent quantum correction to the mass are argued to vanish. Hence the…
We investigate a new scenario of the two Higgs doublet model, where the current experimental data for the electroweak rho parameter and those for the Higgs boson couplings can be simultaneously explained. In this scenario, the two Higgs…
Analysis of the 125 GeV Higgs boson decay rates to two photons and Z plus photon in the Inert Doublet Model is presented. We study the constraints on the masses of the scalars (in particular the Dark Matter candidate) and their couplings to…
Measurements of a Higgs boson at the Large Hadron Collider (LHC) have become increasingly consistent with the predictions of the Standard Model (SM). This fact puts severe constraints on many potential low-energy extensions of the Higgs…
The current LHC Higgs data provide strong constraints on possible deviations of the couplings of the observed 125 GeV Higgs boson from the Standard Model (SM) expectations. Therefore, it now becomes compelling that any extended Higgs sector…
Upper bounds for neutral as well as charged Higgs boson masses in a two-doublet model are obtained on the basis of tree unitarity conditions \`a la Lee, Quigg and Thacker. A wide variety of scattering processes are considered so extensively…
The standard model taken with a momentum space cut-off may be viewed as an effective low energy theory. The structure of it and its known parameters can give us hints for relations between these parameters. In the present investigation the…
The analysis of the Higgs boson data by the ATLAS and CMS Collaborations appears to exhibit an excess of h --> gamma\gamma events above the Standard Model (SM) expectations; whereas no significant excess is observed in h --> ZZ* --> {four…
We investigate origin of three features that are often assumed in analysis of two-Higgs doublet models: (i) softly broken Z2 symmetry, (ii) CP invariant Higgs potential, and (iii) degenerated mass spectra. We extend electroweak gauge…