Normal hierarchy neutrino mass model revisited with leptogenesis

TL;DR

This paper revisits a neutrino mass model with normal hierarchy, exploring leptogenesis within an $A_4$ flavor symmetric framework, and analyzes how additional flavons and right-handed neutrinos influence baryogenesis and neutrino properties.

Contribution

It introduces a model with an extra flavon and right-handed neutrinos to study thermal leptogenesis and its relation to neutrino masses and baryon asymmetry.

Findings

Non-zero reactor mixing angle generated naturally.

Successful computation of matter-antimatter asymmetry for various right-handed neutrino masses.

Correlation established between baryon asymmetry and model parameters.

Abstract

We have studied the scenario of baryogenesis via leptogenesis in an $A_4$ flavor symmetric framework considering type I seesaw as the origin of neutrino mass. Because of the presence of the fifth generation right handed neutrino the model naturally generates non-zero reactor mixing angle. We have considered two vev alignments for the extra flavon $\eta$ and studied the consequences in detail. As a whole the additional flavon along with the extra right handed neutrinos allow us to study thermal leptogenesis by the decay of the lightest right handed neutrino present in the model. We have computed the matter-antimatter asymmetry for both flavor dependent and flavor independent leptogenesis by considering a considerably wider range of right handed neutrino mass. Finally, we correlate the baryon asymmetry of the universe (BAU) with the model parameters and light neutrino masses.