Neutrino mixing with revamped A4 flavour symmetry

TL;DR

This paper proposes a minimal extension to the A4 flavour symmetry model to account for the nonzero theta13 neutrino mixing angle, predicting specific correlations between mixing angles and CP violation.

Contribution

It introduces a novel minimal extension of the A4 model that explains recent neutrino oscillation data and predicts new correlations among mixing parameters.

Findings

Predicts a smaller allowed region for theta23 and theta13

Correlates CP violation with the atmospheric mixing angle octant

Maximal mixing implies CP violation is violated

Abstract

We suggest a minimal extension of the simplest A4 flavour model that can induce a nonzero theta13 value, as required by recent neutrino oscillation data from reactors and accelerators. The predicted correlation between the atmospheric mixing angle theta23 and the magnitude of theta13 leads to an allowed region substantially smaller than indicated by neutrino oscillation global fits. Moreover, the scheme correlates CP violation in neutrino oscillations with the octant of the atmospheric mixing parameter theta23 in such a way that, for example, maximal mixing necessarily violates CP. We briefly comment on other phenomenological features of the model.