Tri-bimaximal neutrino mixing and neutrinoless double beta decay

TL;DR

This paper proposes a tri-bimaximal neutrino mixing model linking neutrinoless double beta decay rates to neutrino mass ratios and CP phases, with specific predictions for decay observability.

Contribution

It introduces a novel neutrino mixing scheme with testable predictions for neutrinoless double beta decay rates based on flavor symmetries and CP phases.

Findings

Decay rate correlates with mass ratio and CP phase.

Rate vanishes at specific CP phase and mass ratio.

Model realizations with A4 flavor symmetries proposed.

Abstract

We present a tri-bimaximal lepton mixing scheme where the neutrinoless double beta decay rate (bb0v) has a lower bound which correlates with the ratio alpha = Dmsol/Dmatm well determined by current data, as well as with the unknown Majorana CP phase phi12 characterizing the solar neutrino sub-system. For the special value phi12 = pi/2 (opposite CP-sign neutrinos) the bb0v rate vanishes at tree level when Dmsol/Dmatm = 3/80, only allowed at 3 sigma. For all other cases the rate is nonzero, and lies within current and projected experimental sensitivities close to phi12=0. We suggest two model realizations of this scheme in terms of an A4xZ2 and A4xZ4 flavour symmetries.