Generalized $\mathbb{Z}_2\times \mathbb{Z}_2$ in Scaling neutrino Majorana mass matrix and baryogenesis via flavored leptogenesis

TL;DR

This paper explores a generalized $ ext{Z}_2 imes ext{Z}_2$ symmetry in a neutrino mass matrix, deriving testable predictions for neutrino parameters and baryogenesis via flavored leptogenesis, with implications for upcoming experiments.

Contribution

It introduces a novel $ ext{Z}_2 imes ext{Z}_2$ symmetric model linking neutrino mixing, CP violation, and leptogenesis, providing analytical relations and experimental predictions.

Findings

Maximal CP violation for Dirac phase

Predicted relations between $ heta_{12}$ and $ heta_{13}$

Constraints on heavy neutrino masses for baryogenesis

Abstract

We investigate the consequences of a generalized $\mathbb{Z}_2\times\mathbb{Z}_2$ symmetry on a scaling neutrino Majorana mass matrix. It enables us to determine definite analytical relations between the mixing angles $\theta_{12}$ and $\theta_{13}$, maximal CP violation for the Dirac type and vanishing for the Majorana type. Beside the other testable predictions on the low energy neutrino parameters such as $\beta\beta_{0\nu}$ decay matrix element $|M_{ee}|$ and the light neutrino masses $m_{1,2,3}$, the model also has intriguing consequences from the perspective of leptogenesis. With the assumption that the required CP violation for leptogenesis is created by the decay of lightest ($N_1$) of the heavy Majorana neutrinos, only $\tau$-flavored leptogenesis scenario is found to be allowed in this model. For a normal (inverted) ordering of light neutrino masses, $\theta_{23}$ is found be less (greater) than its maximal value, for the final baryon asymmetry $Y_B$ to be in the observed range. Besides, an upper and a lower bound on the mass of $N_1$ have also been estimated. Effect of the heavier neutrinos $N_{2,3}$ on final $Y_B$ has been worked out subsequently. The predictions of this model will be tested in the experiments such as nEXO, LEGEND, GERDA-II, T2K, NO$\nu$A, DUNE etc.