Inverse neutrino mass hierarchy in a flavour GUT model

TL;DR

This paper presents a supersymmetric SU(5) x A_4 flavour GUT model that naturally realizes an inverse neutrino mass hierarchy, aligning well with current experimental data and offering testable differences from normal hierarchy models.

Contribution

The paper introduces a novel inverse neutrino mass hierarchy model within a supersymmetric GUT framework, distinct from previous normal hierarchy models, with specific predictions for lepton and quark sectors.

Findings

Model achieves inverse hierarchy without fine-tuning.

Excellent agreement with current experimental data.

Predicts differences in lepton and quark sector observables.

Abstract

We construct a supersymmetric SU(5) x A_4 flavour GUT model in which an inverse neutrino mass hierarchy is realised without fine-tuning of parameters. The model shares some properties with the normal hierarchy model which we presented in arXiv:1305.6612 - in particular the relation theta_13^PMNS = theta_C / sqrt(2). Besides these shared features, there are also important differences, mainly due to the different neutrino sector. These differences not only change the predictions in the lepton sector, but also in the quark sector, and will allow to discriminate between the two models using the results of present and future experiments. From a Markov Chain Monte Carlo fit we find that the inverse hierarchy model is in excellent agreement with the present experimental data.