Type-I thermal leptogenesis in $Z_3$-symmetric three Higgs doublet model

TL;DR

This paper investigates how a $Z_3$-symmetric three Higgs doublet model with right-handed neutrinos can generate neutrino masses and explain the universe's baryon asymmetry through thermal leptogenesis, constrained by scalar sector parameters.

Contribution

It introduces a novel framework combining $Z_3$ symmetry with three Higgs doublets and right-handed neutrinos to simultaneously address neutrino masses and baryon asymmetry via thermal leptogenesis.

Findings

Identifies parameter space consistent with neutrino oscillation data.

Demonstrates successful baryon asymmetry generation within the model.

Establishes bounds on $ an eta$ from scalar sector constraints.

Abstract

Our present work explores the possibility of neutrino mass generation through {\em Type-I see-saw} mechanism and provides an explanation of the baryon asymmetry of the Universe via thermal leptogenesis in the framework of $Z_3$-symmetric three Higgs doublet model (3HDM) augmented with three right-handed neutrinos. Here the thermal leptogenesis is initiated by the out-of-equilibrium decay of the lightest heavy neutrino $N_1$. The constraints arising out of the scalar sector put strong bound on the model parameter $\tan \beta$, which in turn takes part in the computation of the lepton asymmetry $\epsilon$. Lepton asymmetry being converted partially into the baryon asymmetry by electroweak sphelaron processes, will account for the required baryon asymmetry satisfying the current data. We therefore analyse the parameter space consistent with the constraints arising from neutrino oscillation, lepton asymmetry and baryon asymmetry together, last one being the most stringent one.