Related papers: Vacuum Stability Conditions for Higgs Potentials w…
We discuss the phenomenological viability of string multi-Higgs doublet models, namely a scenario of heterotic $Z_3$ orbifolds with two Wilson lines, which naturally predicts three supersymmetric families of matter and Higgs fields. We…
The questions of the origin of electroweak symmetry breaking and neutrino mass are two major puzzles in particle physics. Neutrino mass generation requires new physics beyond the Standard Model and also suggests reconsideration of physics…
We study different types of Two Higgs Doublet Models (2HDMs) under the assumption that all quartic couplings' beta functions vanish simultaneously at the Planck scale. The Standard Model seems to display this property almost accidentally,…
Extending the Standard Model by adding a scalar field transforming as a septet under $SU(2)_L$ preserves the $\rho$ parameter at tree level and can satisfy experimental constraints on the electroweak parameters $S$ and $T$. This work…
We discuss the realization of two Higgs doublets model in the framework of 6 dimensional Gauge-Higgs Unification model with a simple Lie group G_M. Two Higgs SU(2)_L doublets can emerge at the low energy effective theory, and the quartic…
We investigate the stability of Higgs potential in inverse seesaw models. We derive the full two-loop RGEs of the relevant parameters, such as the quartic Higgs self-coupling, taking thresholds into account. We find that for relatively…
In this paper we consider a minimal extension to the standard model by a scalar triplet field with hypercharge $Y=2$. This model relies on the seesaw mechanism which provides a consistent explication of neutrino mass generation. We show…
We investigate the standard model (SM) with the extension of a charged scalar having fractional electromagnetic charge of $-1/3$ unit and with lepton and baryon number violating couplings at tree level. Without directly taking part in the…
String-localized quantum field theory allows renormalizable couplings involving massive vector bosons, without invoking negative-norm states and compensating ghosts. We analyze the most general coupling of a massive vector boson to a scalar…
We perform a systematic study of generic accidental Higgs-family and CP symmetries that could occur in the two-Higgs-doublet-model potential, based on a Majorana scalar-field formalism which realizes a subgroup of GL(8,C). We derive the…
We consider the extension of the Standard electroweak Model through an $SU(2)$ quadruplet of scalars with hypercharge either $3/2$ or $1/2$ (with an additional reflection symmetry in the latter case). We establish, through $\textit{exact…
We compute the electroweak S and T parameters induced by SU(2)_L triplet scalars up to one-loop order. We consider the most general renormalizable potential for a triplet and the Standard Model Higgs doublet. Our calculation is performed by…
We investigate the vacuum stability in a scale invariant local $U(1)_\chi$ model with vanishing scalar potential at the Planck scale. We find that it is impossible to realize the Higgs mass of 125\,GeV while keeping the Higgs quartic…
We determine the next-to-leading order renormalization group equations for the Two-Higgs-Doublet model with a softly broken $Z_2$ symmetry and CP conservation in the scalar potential. We use them to identify the parameter regions which are…
We present the results of a detailed calculation of the excitation spectrum of states with quantum numbers J^{PC}=0++, 1-- and 2++ in the three-dimensional SU(2) Higgs model at two values of the scalar self-coupling and for fixed gauge…
The scalar sector of the simplest version of the 3-3-1 electroweak models is constructed with three Higgs triplets only. We show that a relation involving two of the constants of the Higgs potential, two vacuum expectation values of the…
We show that the vacuum structure of a generic multi-Higgs-doublet model shares several important features with the vacuum structure of the two and three Higgs-doublet model. In particular, one can still define the usual charge breaking,…
We demonstrate that Standard Model vacuum stability exhibits extreme sensitivity to the Higgs quartic coupling: a mere 3\% enhancement represents the critical threshold separating metastability from absolute stability with UV Landau poles.…
There is a good reason why the standard electroweak SU(2) X U(1) gauge model may be supplemented by two Higgs scalar doublets. They may be remnants of the spontaneous breaking of an SU(2) X SU(2) X U(1) gauge symmetry at a much higher…
If the Higgs mass m_H is as low as suggested by present experimental information, the Standard Model ground state might not be absolutely stable. We present a detailed analysis of the lower bounds on m_H imposed by the requirement that the…