Minimal lepton flavour structures lead to non-maximal 2-3 mixing

TL;DR

This paper argues that minimal lepton flavour structures naturally lead to a non-maximal 2-3 mixing angle and a small $ heta_{13}$, consistent with current experimental data, and explores their implications for neutrino properties.

Contribution

It demonstrates that simple, minimal flavour models based on discrete symmetries can explain observed lepton mixing angles and proposes a method to analyze their correlations with neutrino mass parameters.

Findings

Minimal flavour structures predict non-maximal 2-3 mixing.

Models based on discrete symmetries justify small number of parameters.

Correlation between mixing angles, mass scale, and CP phases is established.

Abstract

Present data prefer a large but non-maximal 2-3 mixing in the lepton sector. We argue that this value, in connection with $\sin\theta_{13}\simeq 0.15$, is the generic outcome of minimal flavour structures. We present a few different incarnations of this statement, in terms of lepton mass matrices depending on a small number of parameters, that can be justified by discrete flavour symmetries. We also propose a general procedure to study the correlation between $\theta_{23}$, the absolute scale and ordering of the neutrino masses, and the leptonic CP-violating phases.