Realistic Tri-Bi-Maximal neutrino mixing

Abstract

We propose a generalized version of the Tri-Bi-Maximal (TBM) ansatz for lepton mixing, leading to non-zero reactor angle ${\theta }_{13}$ and CP violation. The latter is characterized by two CP phases. The Dirac phase affecting neutrino oscillations is nearly maximal (${\delta }_{CP}\sim \pm \pi /2$), while the Majorana phase implies narrow allowed ranges for the neutrinoless double beta decay amplitude. The solar angle ${\theta }_{12}$ lies nearly at its TBM value, while the atmospheric angle ${\theta }_{23}$ has the TBM value for maximal ${\delta }_{CP}$. Neutrino oscillation predictions can be tested in present and upcoming experiments.

5 pages, 6 figures