Discrete flavour symmetries for degenerate solar neutrino pair and their predictions

Understand

Flavour symmetries appropriate for describing a neutrino spectrum with degenerate solar pair and a third massive or massless neutrino are discussed.

• We demand that the required residual symmetries of the leptonic mass matrices be subgroups of some discrete symmetry group $G_f$.
• $G_f$ can be a subgroup of SU(3) if the third neutrino is massive and we derive general results on the mixing angle predictions for various discrete subgroups of SU(3).
• The main results are: (a) All the SU(3) subgroups of type C fail in simultaneously giving correct $\theta_{13}$ and $\theta_{23}$.