Relating neutrino masses and mixings by discrete symmetries

TL;DR

This paper explores how discrete flavor symmetries can relate neutrino masses and mixings, deriving specific relations for different degeneracy scenarios and showing how small corrections can adjust these predictions.

Contribution

It introduces an extended framework connecting neutrino mass degeneracies with mixing parameters, including Majorana phases, and analyzes the impact of small corrections.

Findings

Relations between mixing parameters for degenerate neutrino masses

Small corrections can generate observed mass splittings

Predictions for Majorana phases based on degeneracy scenarios

Abstract

Lepton mixing can originate from the breaking of a flavor symmetry in different ways in the neutrino and the charged lepton sector. We propose an extension of this framework which allows to connect the mixing parameters with masses, and more precisely, with certain types of degeneracy of the neutrino mass spectrum. We obtain relations between the mixing parameters for the cases of partial degeneracy, m1 = m2, and complete degeneracy, m1 = m2 = m3. These relations determine also the Majorana phases. It is shown that relatively small corrections to these lowest order results can produce the required mass splitting and modify the mixing without significant changes of the other symmetry results.