Active and sterile neutrino phenomenology with $A_4$ based minimal extended seesaw

TL;DR

This paper explores a neutrino model using the minimal extended seesaw framework with $A_4$ symmetry, addressing active and sterile neutrino phenomenology, leptonic mixing, and leptogenesis within experimental bounds.

Contribution

It introduces a novel $A_4$-based minimal extended seesaw model with broken $-$ symmetry, linking leptonic mixing and sterile neutrino masses to leptogenesis.

Findings

Non-zero reactor mixing angle $ heta_{13}$ naturally arises.

Model viability within $3\sigma$ experimental bounds for sterile neutrino masses.

Extension to leptogenesis with non-degenerate right-handed neutrino masses.

Abstract

We study a model of neutrino within the framework of the minimal extended seesaw (MES), which plays an important role in active and sterile neutrino phenomenology in (3+1) scheme. The $A_4$ flavor symmetry is augmented by an additional $Z_4\times Z_3$ symmetry to constraint the Yukawa Lagrangian of the model. We use non-trivial Dirac mass matrix, with broken $\mu-\tau$ symmetry, as the origin of leptonic mixing. Interestingly, such a structure of mixing naturally leads to the non-zero reactor mixing angle $\theta_{13}$. Non-degenerate mass structure for right-handed neutrino $M_R$ is considered so that we can further extend our study to Leptogenesis. We have also considered three different cases for sterile neutrino mass, $M_S$ to check the viability of this model, within the allowed $3\sigma$ bound in this MES framework.