Related papers: Assessing Perturbativity and Vacuum Stability in H…
A seesaw mechanism is presented in the neutrino sector and a new phase of CP violation ($\alpha$) emerges in the interplay between the type-I and type-III seesaw schemes. This phase is inside the mixing term, and thus it cannot be rotated…
We study the vacuum stability and perturbativity conditions in the minimal type-II seesaw model. These conditions give characteristic constraints to model parameters. In the model, there is a $SU(2)_L$ triplet scalar field, which could…
The generation of the right amount of baryon asymmetry $\eta$ of the Universe from supersymmetric leptogenesis is studied within the type-I seesaw framework with three heavy singlet Majorana neutrinos $N_i\,\,(i = 1,2,3)$ and their…
Testing the stability of the electroweak vacuum in any extension of the Standard Model Higgs sector is of great importance to verify the consistency of the theory. Multi-scalar extensions as the Minimal Supersymmetric Standard Model…
In a minimal model of leptogenesis, the observed baryon asymmetry is realized after high-scale reheating into the lightest sterile neutrino. We consider constraints on this scenario from the stability of the Higgs vacuum during pre-heating.…
We propose a novel scenario to explain the matter-antimatter asymmetry by twofold leptogenesis, wherein heavy Majorana neutrinos exhibit temperature-dependent masses and engage in $CP$-violating decays. This scenario envisages two distinct…
We construct a model of decaying, TeV-scale scalar dark matter motivated by data from the PAMELA and Fermi-LAT experiments. By introducing an appropriate Abelian discrete symmetry and an intermediate scale of vector-like states that are…
We investigate the viability of electroweak baryogenesis in a model with a first order electroweak phase transition induced by the addition of two gauge singlet scalars. A vector-like lepton doublet is introduced in order to provide CP…
We study a real scalar septuplet model which has a neutral component regarded as a dark matter particle candidate. The calculation of its thermal relic abundance without (with) the Sommerfeld effect suggests that the observed value…
Seesaw models with a slightly broken lepton number symmetry can explain small neutrino masses, and allow for low-scale leptogenesis. We make a thorough analysis of leptogenesis within the simplest model with two right-handed (RH) neutrinos…
We provide a set of theoretical constraints on models in which the Standard Model field content is extended by vector-like fermions and in some cases also by a real scalar singlet. Our approach is based on the study of electroweak vacuum…
Recently, Qu and Ding, have proposed a formalism where modular invariance is extended to non-supersymmetric scenario considering Yukawa couplings as non-holomorphic functions of modules field $\tau$. Adopting this formalism in this work, we…
For strong enough Yukawa coupling the electroweak standard model fermion finds it energetically advantageous to transform itself into a bound state in the hedgehog background of Higgs field in semiclassical approximation. By considering the…
In the context of the minimal supersymmetric seesaw model, we study the implications of the current neutrino data for thermal leptogenesis, $\beta\beta_{0\nu}$ decay, and leptonic flavour- and CP-violating low-energy observables. We express…
The Type-II seesaw model is a well-motivated new physics scenario to address the origin of the neutrino mass issue. We show that this model can easily accommodate an absolutely stable vacuum until the Planck scale, however with strong limit…
We show how leptogenesis can occur at the TeV scale with neutrinos that possess almost purely Dirac masses and negligible Majorana mass contributions as a consequence of the small wavefunction overlap in a warped fifth dimension. Lepton…
The Higgs boson discovery at the LHC with a mass of approximately 126 GeV suggests, that the electroweak vacuum of the standard model may be metastable at very high energies. However, any new physics beyond the standard model can change…
In the context of Standard Model (SM) extensions, the seesaw mechanism provides the most natural explanation for the smallness of neutrino masses. In this work we consider the most economical type-I seesaw realization in which two…
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…
We consider a restricted Type-I seesaw scenario with four texture zeros in the neutrino Yukawa matrix, in the weak basis where both the charged-lepton Yukawa matrix and the Majorana mass matrix for right-handed neutrinos are diagonal and…