Neutrino Mixing and Leptogenesis in $\mu-\tau$ Symmetry

TL;DR

This paper explores how a $Z_2$-symmetry in neutrino mass matrices influences neutrino mixing and leptogenesis, demonstrating its compatibility with observed data and baryon asymmetry through a specific high-scale perturbation model.

Contribution

It implements $rac12$-symmetry in the type-I seesaw mechanism, showing how it can explain neutrino data and baryon asymmetry with a high-scale perturbation.

Findings

The $Z_2$-symmetry can generate sufficient lepton asymmetry.

A specific high-scale perturbation model reproduces neutrino mixing data.

The model accommodates various lepton mass hierarchies.

Abstract

We study the consequences of the $Z_2$-symmetry behind the $\mu$--$\tau$ universality in neutrino mass matrix. We then implement this symmetry in the type-I seesaw mechanism and show how it can accommodate all sorts of lepton mass hierarchies and generate enough lepton asymmetry to interpret the observed baryon asymmetry in the universe. We also show how a specific form of a high-scale perturbation is kept when translated via the seesaw into the low scale domain, where it can accommodate the neutrino mixing data. We finally present a realization of the high scale perturbed texture through addition of matter and extra exact symmetries.