1203.4185 (Y. H. Ahn et al.)

Non-zero $θ_{13}$ and CP violation in a model with $A_4$ flavor
symmetry    [PDF]

Y. H. Ahn, Sin Kyu Kang

Motivated by $5.2\sigma$ observation of non-zero $\theta_{13}$ from the Daya Bay experiment, we propose a renormalizable neutrino model with $A_4$ discrete symmetry accounting for deviations from the tri-bimaximal (TBM) mixing pattern of neutrino mixing matrix indicated by neutrino oscillation data. In the model, the light neutrino masses can be generated by radiative corrections, and we show how the light neutrino mass matrix can be diagonalized by the PMNS mixing matrix whose entries are determined by the current neutrino data including the Daya Bay result. We show that the origin of the deviations from the TBM mixing is non-degeneracy of the neutrino Yukawa coupling constants, and unremovable CP phases in the neutrino Yukawa matrix give rise to the low energy CP violation measurable from neutrino oscillation as well as high energy CP violation required for leptogenesis.

View original: http://arxiv.org/abs/1203.4185