Combining texture zeros with a remnant CP symmetry in the minimal type-I seesaw

TL;DR

This paper explores how combining texture zeros with a remnant CP symmetry in a minimal type-I seesaw model constrains neutrino properties, aligning with current experimental data and predicting CP phases and decay parameters.

Contribution

It introduces a novel analysis of texture-zero patterns combined with remnant CP symmetry in a minimal seesaw model, detailing their compatibility with recent neutrino data.

Findings

Certain texture-zero patterns are compatible with current neutrino oscillation data.

Allowed zero patterns depend on the heavy neutrino mass spectrum.

Predictions for CP-violating phases and neutrinoless double-beta decay parameters are provided.

Abstract

In the framework of the two right-handed neutrino seesaw model, we consider maximally-restrictive texture-zero patterns for the lepton Yukawa coupling and mass matrices, together with the existence of a remnant CP symmetry. Under these premisses, we find that several textures are compatible with the most recent data coming from neutrino oscillation and neutrinoless double beta decay experiments. It is shown that the number of allowed texture zeros depends on the type of heavy right-handed neutrino mass spectrum. Namely, at most one (two)-zero patterns are allowed in the Dirac Yukawa coupling matrix for nondegenerate (degenerate) heavy Majorana neutrinos. The predictions for the low-energy Dirac and Majorana CP-violating phases, and for the effective mass parameter relevant in neutrinoless double-beta decay experiments, are presented and discussed. We also comment on the impact of future experimental improvements in scrutinising texture-zero patterns with a remnant CP symmetry, within the minimal version of the seesaw mechanism considered here.