Related papers: Cornering variants of Georgi-Machacek model using …
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…
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 explore the implications of a 126 GeV Higgs boson indicated by the recent LHC results for two-Higgs doublet model (2HDM). Identifying the 126 GeV Higgs boson as either the lighter or heavier of CP even neutral Higgs bosons in 2HDM, we…
One-loop contributions to the Higgs potential at finite temperatures are discussed in the supersymmetric standard model with four Higgs doublet chiral superfields as well as a pair of charged singlet chiral superfields. The mass of the…
The combined CMS and ATLAS analysis of \(h \to Z\gamma\) reveals a \(2\sigma\) excess over the Standard Model (SM) prediction, hinting at potential new physics. In contrast, the observed agreement of \(\mu_{\gamma\gamma}\) with the SM…
We analyze the collider signals of composite scalars that emerge in certain little Higgs models and models of vectorlike confinement. Similar to the decay of the pion into photon pairs, these scalars mainly decay through anomaly-induced…
We consider the electroweak theory with an additional Higgs triplet at one loop using the hybrid renormalization scheme based on $\alpha_{\rm EM}$, $G_F$ and $M_Z$ as input observables. We show that in this scheme loop corrections can be…
We revisit the stability of the Standard Model vacuum, and investigate its quantum effective potential using the highest available orders in perturbation theory and the most accurate determination of input parameters to date. We observe…
We extract constraints on the parameter space of the MW model by comparing the cross-sections for dijet, top-pair, dijet-pair, $t\bar t t \bar t$ and $b\bar b b \bar b$ productions at the LHC with the strongest available experimental limits…
If the di-photon excess at 750 GeV hinted by the 2015 data at the LHC is explained in terms of a scalar resonance participating in the breaking of the electro-weak symmetry, this resonance must be accompanied by other scalar states for…
We update the constraints on two-Higgs-doublet models (2HDMs) focusing on the parameter space relevant to explain the present muon $g$$-$$2$ anomaly, $\Delta a_{\mu}$, in four different types of models, type I, II, "lepton specific" (or X)…
We examine the level of enhancement that can be achieved in the ZZ and \gamma\gamma channels for a two-Higgs-doublet model Higgs boson (either the light h or the heavy H) with mass near 125 GeV after imposing all constraints from LEP data,…
We review the THDM model in which one of the Higgs doublets does not develop a vacuum expectation value. In this case, the Higgs fields with zero VEV does not contribute to the physical masses of the SM particles, and hence, its…
The minimal supersymmetric standard model, and extensions, have stringent upper bounds on the mass of the lightest Higgs boson if perturbativity up to the Planck scale is assumed. We argue that these bounds are softened tremendously if the…
One of the cleanest signatures of a heavy Higgs boson in models with vectorlike leptons is $H\to e_4^\pm \ell^\mp \to h\ell^+\ell^-$ which, in two Higgs doublet model type-II, can even be the dominant decay mode of heavy Higgses. Among the…
Type-Z models, where charged leptons, up type quarks, and down type quarks each couple to a different scalar, are only possible when there are three or more Higgs doublets. We consider the Type-Z three Higgs doublet model imposed by a…
LHC results do not confirm conventional natural solutions to the Higgs mass hierarchy problem, motivating alternative interpretations where a hierarchically small weak scale is generated from a dimension-less quantum dynamics. We propose…
We analyse effective potential around the electroweak (EW) scale in the Standard Model extended with a heavy scalar doublet. We show that the additional scalars can have a strong impact on vacuum stability. Although the additional heavy…
We investigate the search for doubly charged Higgs bosons in the Georgi-Machacek (GM) model at same-sign lepton colliders. The dominant production mode is vector boson fusion, through which the particle is singly produced and decays into a…
We study the Higgs-boson mass spectrum of a classical scale-invariant realization of the two-Higgs-doublet model (SI-2HDM). The classical scale symmetry of the theory is explicitly broken by quantum loop effects due to gauge interactions,…