Parallel hybrid textures of lepton mass matrices

TL;DR

This paper investigates specific structured patterns in lepton mass matrices, revealing their physical implications, classifying them into groups, and analyzing their phenomenological consequences for neutrino mixing and CP violation.

Contribution

It introduces a classification of parallel hybrid textures in lepton mass matrices and explores their physical and phenomenological implications, including constraints on CP phases and Majorana mass.

Findings

Five classes are phenomenologically disallowed.

Constraints on Majorana mass are derived for allowed classes.

Allowed classes provide specific predictions for neutrino mixing angles and CP phases.

Abstract

We analyse the parallel hybrid texture structures in the charged lepton and the neutrino sector. These parallel hybrid texture structures have physical implications as they cannot be obtained from arbitrary lepton mass matrices through weak basis transformations. The total sixty parallel hybrid texture structures can be grouped into twelve classes, and all the hybrid textures in the same class have identical physical implications. We examine all the twelve classes under the assumption of non-factorizable phases in the neutrino mass matrix. Five out of the total twelve classes are found to be phenomenologically disallowed. We study the phenomenological implications of the allowed classes for 1-3 mixing angle, Majorana and Dirac-type $CP$ violating phases. Interesting constraints on effective Majorana mass are obtained for all the allowed classes.