Residual Symmetries for Neutrino Mixing with a Large theta_13 and Nearly Maximal delta_D

TL;DR

This paper explores residual symmetries in neutrino mixing, deriving relations for mixing angles and CP phases that align with current experimental data, and predicts distributions for these parameters for future testing.

Contribution

It introduces a novel connection between residual Z2 symmetries and neutrino mixing parameters, providing specific predictions consistent with existing measurements.

Findings

Predicted theta_13 around 3-6 degrees with 2-4 degree uncertainty.

Predicted CP phase delta_D peaks near +-74 and +-123 degrees.

Results align with T2K, MINOS, Double CHOOZ, and global fit data.

Abstract

The residual Z^s_2(k) and bar Z^s_2(k) symmetries induce a direct and unique phenomenological relation with theta_x (= theta_13) expressed in terms of the other two mixing angles, theta_s (= theta_12) and theta_a (= theta_23), and the Dirac CP phase delta_D. Z^s_2(k) predicts a theta_x probability distribution centered around 3^o ~ 6^o with an uncertainty of 2^o to 4^o while those from bar Z^s_2(k) are approximately a factor of two larger. Either result fits the T2K, MINOS and Double CHOOZ measurements. Alternately a prediction for the Dirac CP phase delta_D results in a peak at +-74^o (+-106^o) for Z^s_2(k) or +-123^o (+-57^o) for bar Z^s_2(k) which is consistent with the latest global fit. We also give a distribution for the leptonic Jarslkog invariant J_v which can provide further tests from measurements at T2K and NOvA.