Quasi-degenerate neutrinos and tri-bi-maximal mixing

TL;DR

This paper studies how radiative corrections influence neutrino mixing angles in supersymmetric models with quasi-degenerate neutrinos and tri-bi-maximal mixing, establishing high-energy scale constraints and proposing a symmetry-based model.

Contribution

It introduces a model with a non-Abelian discrete family symmetry that naturally yields quasi-degenerate neutrino masses and near tri-bi-maximal mixing.

Findings

Radiative running affects neutrino mixing angles from high to low energy.

Constraints on the high-energy scale are derived for consistency with observed mixing.

A symmetry-based model explains the quasi-degenerate spectrum and mixing pattern.

Abstract

We consider how, for quasi-degenerate neutrinos with tri-bi-maximal mixing at a high-energy scale, the mixing angles are affected by radiative running from high to low-energy scales in a supersymmetric theory. The limits on the high-energy scale that follow from consistency with the observed mixing are determined. We construct a model in which a non-Abelian discrete family symmetry leads both to a quasi-degenerate neutrino mass spectrum and to near tri-bi-maximal mixing.