Two/Three-Flavor Oscillation and MSW/Vacuum Oscillation Solution of Neutrinos in the SO(3) Gauge Model

TL;DR

This paper explores three neutrino mixing scenarios within a gauged SO(3) lepton flavor symmetry model, identifying the nearly bi-maximal mixing scenario as most consistent with solar and atmospheric neutrino data, and analyzing neutrino mass implications.

Contribution

It introduces a gauged SO(3) flavor symmetry model and evaluates three neutrino mixing scenarios, highlighting the nearly bi-maximal mixing scenario's reliability in data reconciliation.

Findings

Nearly bi-maximal mixing best fits solar and atmospheric neutrino data.

Neutrino masses can be large enough for cosmological significance in certain scenarios.

Mass fraction /_m constrained in the small-large mixing scenario.

Abstract

Three interesting scenarios for neutrino mixing, i.e., (i) small-large mixing scenario, (ii) nearly bi-maximal mixing scenario and (iii) three-flavor oscillation scenario, are analyzed in connection with three possible assignments of the maximal CP-violating phase after spontaneous symmetry breaking of SO(3) in a model with gauged SO(3) lepton flavor symmetry. As a consequence, it is found that the scenario (ii) is more reliable to be resulted in reconciling both solar and atmospheric neutrino data. Though three Majorana neutrino masses in all scenarios can be nearly degenerate, in the scenarios (ii) and (iii) masses of the neutrinos are allowed to be large enough to play a significant cosmological role and in the scenario (i) the fraction $\Omega_{\nu}/\Omega_{m}$ is bounded to be $\Omega_{\nu}/\Omega_{m} < (4-10)%$ for $\Omega_{m} = (1.0-0.4)$ and $h=0.6$.