Realistic Tri-Bi-Maximal neutrino mixing

TL;DR

This paper introduces a generalized Tri-Bi-Maximal neutrino mixing model that predicts non-zero reactor angle and CP violation, with specific phase characteristics, testable in current and future experiments.

Contribution

It extends the TBM ansatz to include CP violation and non-zero reactor angle, providing new testable predictions for neutrino oscillation parameters.

Findings

Dirac CP phase is nearly maximal (~±π/2).

Narrow ranges predicted for neutrinoless double beta decay.

Solar angle remains close to TBM value.

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.