SO(3) Gauge model for neutrino masses and oscillations

TL;DR

This paper presents an $SO(3)_F$ gauge model explaining neutrino masses and oscillations, naturally producing maximal and bi-maximal mixing patterns, with implications for cosmology and lepton-flavor violation.

Contribution

It introduces a gauge model with $SO(3)_F$ symmetry and two Higgs triplets that naturally explains observed neutrino mixing patterns and mass hierarchies.

Findings

Maximal mixing between $ u_{}$ and $ u_{ au}$ emerges naturally.

Nearly degenerate Majorana neutrino masses can be cosmologically significant.

The model predicts potential lepton-flavor violation phenomena.

Abstract

I mainly describe neutrino masses and oscillations in the gauge model with $SO(3)_{F}$ lepton flavor symmetry and with two Higgs triplets. It is shown how the maximal mixing between $\nu_{\mu}$ and $\nu_{\tau}$ neutrinos comes out naturally after spontaneous breaking of the symmetry. The nearly two-flavor mixing scenario is resulted naturally from an approximate permutation symmetry between the two Higgs triplets. The hierarchy between the neutrino mass-squared differences, which is needed for reconciling both solar and atmospheric neutrino data, leads to an almost maximal mixing between $\nu_{e}$ and $\nu_{\mu}$ neutrinos. Thus the model favors the intriguing bi-maximal mixing scenario.The three Majorana neutrino masses are allowed to be nearly degenerate and large enough to play a significant cosmological role. The model can also lead to interesting phenomena on lepton-flavor violations via the $SO(3)_{F}$ gauge interactions.