Spontaneous Breaking of Flavor Symmetry and Naturalness of Nearly Degenerate Neutrino Masses and Bi-maximal Mixing

TL;DR

This paper presents a gauge model with $SO(3)_F$ flavor symmetry that naturally explains nearly degenerate neutrino masses and bi-maximal mixing through spontaneous symmetry breaking, also predicting lepton-flavor violation effects.

Contribution

It introduces a novel $SO(3)_F$ gauge model that naturally accounts for neutrino mass degeneracy and mixing patterns, linking symmetry breaking to observed neutrino phenomena.

Findings

Neutrino masses are nearly degenerate due to spontaneous symmetry breaking.

The model explains the hierarchy of neutrino mass-squared differences.

Predicts lepton-flavor violation effects via $SO(3)_F$ gauge interactions.

Abstract

The gauge model with $SO(3)_{F}$ flavor symmetry and three Higgs triplets is studied. We show how the intriguing nearly degenerate neutrino mass and bi-maximal mixing scenario comes out naturally after spontaneous breaking of the symmetry. The hierarchy between the neutrino mass-squared differences, which is needed for reconciling both solar and atmospheric neutrino data, is naturally resulted from an approximate permutation symmetry. The model can also lead to interesting phenomena on lepton-flavor violations via the $SO(3)_{F}$ gauge interactions.