Five models for lepton mixing

TL;DR

This paper introduces five distinct lepton flavor models based on the type-I seesaw mechanism, each fitting current neutrino data and making specific predictions for neutrino mass scales and mixing phases.

Contribution

The paper presents five new lepton flavor models incorporating symmetries and the seesaw mechanism, with detailed predictions for neutrino properties.

Findings

All models fit neutrino oscillation data at one-sigma level.

Models predict specific neutrino mass scales and CP phase delta.

One model predicts a correlation between mixing angles theta_12 and theta_23.

Abstract

We produce five flavour models for the lepton sector. All five models fit perfectly well---at the one-sigma level---the existing data on the neutrino mass-squared differences and on the lepton mixing angles. The models are based on the type-I seesaw mechanism, on a Z_2 symmetry for each lepton flavour, and either on a (spontaneously broken) symmetry under the interchange of two lepton flavours or on a (spontaneously broken) CP symmetry incorporating that interchange---or on both symmetries simultaneously. Each model makes definite predictions both for the scale of the neutrino masses and for the phase delta in lepton mixing; the fifth model also predicts a correlation between the lepton mixing angles theta_12 and theta_23.