Related papers: The decoupling limit in the Georgi-Machacek model
We study the heavy Higgs sector of the MSSM composed of the H^\pm, H^0 and A^0 particles in the so-called decoupling limit where m_{A^0} >> m_Z. By integrating out these heavy Higgs particles to one-loop, we compute the effective action for…
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…
Depending on the Higgs-boson and top-quark masses, $M_H$ and $M_t$, the effective potential of the {\bf Standard Model} can develop a non-standard minimum for values of the field much larger than the weak scale. In those cases the standard…
We study the phenomenology of the Standard Model (SM) Higgs sector extended by two singlet scalars. The model predicts two CP-even scalars $h_{1,2}$ which are a mixture of doublet and singlet components as well as a pure singlet scalar…
The Georgi-Machacek (GM) model is a triplet scalar extension of the Standard Model (SM) that preserves custodial symmetry (CS) due to an explicit global $SU(2)_L\otimes SU(2)_R$ symmetry in the scalar potential at tree-level. However, it is…
We calculate a full set of one-loop corrections to the Higgs boson coupling constants as well as the electroweak parameters. We compute the decay rate of the standard model (SM)-like Higgs boson ($h$) into diphoton. Renormalized Higgs…
We investigate the scalar sector in an extension of the Minimal Supersymmetric Standard Model (MSSM) containing a $SU(2)$ Higgs triplet of zero hypercharge and a gauge singlet beside the $SU(2)$ scalar doublets. In particular, we focus on a…
We perform a comprehensive study of the Higgs sector of the Minimal Supersymmetric extension of the Standard Model in the case where all Higgs bosons are rather light, with masses of ${\cal O}(100 GeV)$, and couple maximally to electroweak…
We study Higgs boson couplings in the large-$\lambda$ version of the Next-to-Minimal Supersymmetric Standard Model, known as $\lambda$-SUSY. We find that the predicted deviations from the Standard Model (SM) in these couplings are inversely…
In the MSSM, the Higgs couplings to down-type quarks and leptons, normalized with respect to their corresponding Standard Model values, coincide at tree-level and this degeneracy is only slightly broken at the quantum level. Motivated by…
The heavy, doublet-dominated Higgs bosons expected in Two-Higgs-Doublet-Model-like extensions of the Standard Model are obvious targets for searches at high-energy colliders, and considerable activity in this sense is currently employed in…
Physics beyond the Standard Model (SM) may manifest itself as small deviations from the SM predictions for Higgs signal strengths at 125 GeV. Then, a plausible and interesting possibility is that the Higgs sector is extended and at the weak…
We study how the dominant single and double SM-like Higgs ($h$) production at future $e^+e^-$ colliders is modified in the Georgi-Machacek (GM) model. On imposing theoretical, indirect and direct constraints, significant deviations of…
The Large Electron-Positron (LEP) collider experiments have constrained the mass of the Standard Model (SM) Higgs boson to be above 114.4 GeV. This bound applies to all extensions of the SM where the coupling of a Higgs boson to the Z boson…
We investigate possible symmetry properties of the scalar sector of Multi-Higgs-Doublet Models, and, to some extent, the generalization of such models to gauge groups other than $SU(2)_L\times U(1)_Y$. In models where the ${\cal C}$ (charge…
We propose a simple gauge extension of the minimal supersymmetric standard model (MSSM), where the fine tuning in the Higgs mass parameters is highly reduced. The Higgs boson is insensitive to high energies because of supersymmetry and also…
In the ``non-decoupling'' region of the Higgs sector in MSSM, the heavier CP-even Higgs boson (H^0) is Standard-Model-like and close to the charged Higgs bosons (H^\pm) in mass, while other neutral Higgs bosons (h^0,A^0) are lighter and…
We study new physics effects on the couplings of weak gauge bosons with the lightest CP-even Higgs boson ($h$), $hZZ$, and the tri-linear coupling of the lightest Higgs boson, $hhh$, at the one loop order, as predicted by the two Higgs…
We study a supersymmetric extension of the SM with Higgs triplets in the scalar sector. We begin with a review of the SM, particularly the Higgs mechanism. In the SM, the Higgs mechanism requires the presence of a complex Higgs doublet to…
The $H\to ZZ$ decay mode is usually considered as one of the most promising ways to discover new heavy neutral scalar $H$. We show that in the Georgi-Machacek model it is possible to get large enhancement of double SM-like Higgs boson…