Deviation from tri-bimaximal neutrino mixing in A4 flavor symmetry

Abstract

The tri-bimaximal mixing is a good approximation for the present data of neutrino mixing angles. The deviation from the tri-bimaximal mixing is discussed numerically in the framework of the A4 model. Values of ²θ₁₂, ² 2θ₂₃ and |U_e3| deviate from the tri-bimaximal mixing due to the corrections of the vacuum alignment of flavon fields. It is remarked that ² 2θ₂₃ deviates scarcely from 1 while ²θ₁₂ can deviate from 1/3 considerably and θ₁₃ could be near the present experimental upper bound. The CP violating measure J_CP and the effective Majorana neutrino mass m_ee are also discussed.