A Bottom-Up Approach to Lepton Flavor and CP Symmetries

TL;DR

This paper presents a model-independent framework analyzing residual symmetries in lepton mixing, highlighting the role of Majorana phases and exploring implications for CP violation in neutrino physics.

Contribution

It introduces a novel, model-independent method to study residual Klein and generalized CP symmetries in lepton mixing, emphasizing the significance of Majorana phases.

Findings

Reproduces known mixing patterns like tribimaximal and bitrimaximal.

Provides insights into the origin of the Dirac CP phase.

Analyzes a specific golden ratio mixing pattern.

Abstract

We perform a model-independent analysis of the possible residual Klein and generalized CP symmetries associated with arbitrary lepton mixing angles in the case that there are three light Majorana neutrino species. This approach emphasizes the unique role of the Majorana phases and provides a useful framework in which to discuss the origin of the Dirac CP phase in scenarios with spontaneously broken flavor and generalized CP symmetries. The method is shown to reproduce known examples in the literature based on tribimaximal and bitrimaximal mixing patterns, and is used to investigate these issues for the case of a particular (GR1) golden ratio mixing pattern.