Transformative A_4 Mixing of Neutrinos with CP Violation

Abstract

A new theoretical insight into the pattern of neutrino mixing and leptonic $CP$ violation is presented. It leads naturally and uniquely to a specific dark sector of three real neutral scalar singlets, with the radiative implementation of the inverse seesaw mechanism for neutrino mass. The new simple but crucial enabling idea is that a familiar $A_4$ transformation turns any orthogonal $3\times 3$ matrix into one which predicts ${\theta }_{23}=\pi /4$ and ${\delta }_{CP}=\pm \pi /2$ for the neutrino mixing matrix, in good agreement with present data.

Comments: 11 pages, 2 figures, version to appear in PRD(RC)