Minimal see-saw model predicting best fit lepton mixing angles

TL;DR

This paper presents a minimal see-saw model with specific neutrino coupling patterns derived from symmetry considerations, accurately predicting lepton mixing angles and CP phase consistent with current experimental data.

Contribution

It introduces a novel minimal see-saw model with symmetry-based coupling patterns that precisely predict lepton mixing angles and CP phase.

Findings

Predicts lepton mixing angles theta12=34°, theta23=41°, theta13=9.5°

Predicts CP phase delta=106°

Aligns with current best fit neutrino oscillation data

Abstract

We discuss a minimal predictive see-saw model in which the right-handed neutrino mainly responsible for the atmospheric neutrino mass has couplings to (nu_e, nu_mu, nu_tau) proportional to (0,1,1) and the right-handed neutrino mainly responsible for the solar neutrino mass has couplings to (nu_e, nu_mu, nu_tau) proportional to (1,4,2), with a relative phase eta = -2pi/5. We show how these patterns of couplings could arise from an A_4 family symmetry model of leptons, together with Z_3 and Z_5 symmetries which fix eta = -2pi/5 up to a discrete phase choice. The PMNS matrix is then completely determined by one remaining parameter which is used to fix the neutrino mass ratio m_2/m_3. The model predicts the lepton mixing angles theta12=34 degrees, theta23=41 degrees, theta13=9.5 degrees, which exactly coincide with the current best fit values for a normal neutrino mass hierarchy, together with the distinctive prediction for the CP violating oscillation phase delta =106 degrees.