Related papers: Triviality and vacuum stability bounds in the thre…
We study the electroweak vacuum stability in Type I seesaw models for 3 generations of neutrinos in scenarios where the right-handed neutrinos have explicit bare mass terms in the Lagrangian and where these are dynamically generated through…
Contrary to the common lore based on naive dimensional analysis, the seesaw scale for neutrino masses can be naturally in the TeV range, with small parameters coming from radiative corrections. We present one such class of type-I seesaw…
The scale of neutrino masses and the Planck scale are separated by more than twenty-seven order of magnitudes. However, they can be linked by imposing the stability of the electroweak (EW) vacuum. The crucial ingredient is provided by the…
We investigate the stability of the scalar potential in a minimal $U(1)'$ extension of the Standard Model augmented by an extra complex scalar and three right handed neutrinos. We consider a type-I seesaw scenario for the generation of the…
We investigate a minimal $U(1)'$ extension of the Standard Model with one extra complex scalar and generic gauge charge assignments. We use a type-I seesaw mechanism with three heavy right handed neutrinos to illustrate the constraints on…
We consider the minimal seesaw model in which two gauge singlet right handed neutrinos with opposite lepton numbers are added to the Standard Model. In this model, the smallness of the neutrino mass is explained by the tiny lepton number…
We analyze the stability of the electroweak vacuum in neutrino mass models containing right handed neutrinos or fermionic isotriplets. In addition to considering absolute stability, we place limits on the Yukawa couplings of new fermions…
A novel scenario is presented within the Type-I seesaw mechanism in which no other beyond Standard Model fields except three heavy right handed neutrinos, have been considered. Light neutrino masses around sub eV scale, could be possible at…
We consider singlet extensions of the standard model, both in the fermion and the scalar sector, to account for the generation of neutrino mass at the TeV scale and the existence of dark matter respectively. For the neutrino sector we…
We consider the requirements that all coupling constants remain perturbative and the electroweak vacuum metastable up to the Planck scale in high-scale thermal leptogenesis, in the context of a type-I seesaw mechanism. We find a large…
In this talk, we discuss the phenomenology of radiative 3-loop seesaw models. The 3-loop suppression allows the new particles to have masses at the TeV scale, along with relatively large Yukawa couplings, while retaining consistency with…
This article considers three non-zero hypercharge triplets as an extension of the Standard Model Higgs doublet. Under extra $U(1)_{L_{\mu}-L_{\tau}}$ symmetry, the triplets are charged. We examine the stability of the electroweak vacuum at…
We consider a variant of TeV scale seesaw models in which three additional heavy right handed neutrinos are added to the standard model to generate the quasi-degenerate light neutrinos. This model is theoretically interesting since it can…
The triviality and vacuum stability bounds on the Higgs-boson mass were revisited in presence of weakly-coupled new interactions parameterized in a model-independent way by effective operators of dimension 6. It was shown that for the scale…
We propose a model to explain tiny masses of neutrinos with the lepton number conservation, where neither too heavy particles beyond the TeV-scale nor tiny coupling constants are required. Assignments of conserving lepton numbers to new…
Electroweak Baryogenesis, given a first order phase transition, does not work in the standard model because the quark Yukawa matrices are too hierarchical. On the other hand, the neutrino mass matrix is apparently not hierarchical. In…
We perform a thorough scan of the parameter space of a general singlet scalar extension of the Standard Model to identify the regions which can lead to a strong first-order phase transition, as required by the electroweak baryogenesis…
The Standard Model electroweak vacuum has been found to be metastable, with the true stable vacuum given by a large, phenomenologically unacceptable vacuum expectation value $\approx M_{P}$. Moreover, it may be unstable in an inflationary…
We investigate the electroweak vacuum stability in an extended version of the Standard Model which incorporates two additional singlet scalar fields and three right handed neutrinos. One of these extra scalars plays the role of dark matter…
We study the allowed parameter space of the scalar sector in the superweak extension of the standard model (SM). The allowed region is defined by the conditions of (i) stability of the vacuum and (ii) perturbativity up to the Planck scale,…