SO(3) gauge symmetry and neutrino-lepton flavor physics

Abstract

Based on the SO(3) gauge symmetry for three family leptons and the general seesaw mechanism, we present a simple scheme that allows three nearly degenerate Majorana neutrino masses needed for hot dark matter. The vacuum structure of the spontaneous SO(3) symmetry breaking can automatically lead to a maximal $\mathrm{CP}$-violating phase. Thus the current neutrino data on both the atmospheric neutrino anomaly and solar neutrino deficit can be accounted for via maximal mixings without conflict with the current data on the neutrinoless double $\ensuremath{\beta}$ decay. The model also allows rich interesting phenomena on lepton flavor violations.