Texture of One Equality in Neutrino Mass Matrix

TL;DR

This paper investigates specific textures of the Majorana neutrino mass matrix characterized by a single equality between elements, identifying viable patterns and their symmetry realizations across different neutrino mass hierarchies.

Contribution

It systematically analyzes texture structures with one equality in the neutrino mass matrix and provides symmetry models for some patterns within various seesaw frameworks.

Findings

Fourteen textures are viable in both hierarchies.

One texture is only viable in normal hierarchy.

Symmetry realizations are constructed for some patterns.

Abstract

We carry out a phenomenological and analytical study of the texture structures for the Majorana neutrino mass matrix characterized by one single equality between two independent matrix elements, with vanishing non-physical phases whose role in the definition we clarify. We find that fourteen textures are viable in both types of hierarchy, whereas the remaining fifteenth one is viable only in normal hierarchy. We also present symmetry realizations for some patterns by using Abelian flavor symmetries within type-I, type-II and mixed type-(I+II) seesaw scenarios.