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

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.