Two Zero Mass Matrices and Sterile Neutrinos

TL;DR

This paper explores two-zero textures in neutrino mass matrices within a 3+1 sterile neutrino framework, identifying 15 textures consistent with observations and analyzing their implications for neutrino mass spectra and neutrinoless double beta decay.

Contribution

It systematically classifies two-zero textures in a 3+1 neutrino model and finds which are compatible with current data, extending previous three-neutrino analyses.

Findings

15 consistent two-zero textures identified

Textures correspond to those of three active neutrino models

Predictions for neutrinoless double beta decay effective mass

Abstract

Recent experimental data is indicative of the existence of sterile neutrinos. The minimal scheme that can account for the data and is consistent with cosmological observations is the 3+1 picture which consists of three predominantly active and one predominantly sterile neutrino with the fourth neutrino being heavier than the other three. Within this scheme there are two possibilities depending on whether the three light states obey normal or inverted hierarchy. In this paper we consider the two zero textures of the low energy neutrino mass matrix in presence of one additional sterile neutrino. We find that among 45 possible two zero textures for this case, 15 are consistent with all current observations. Remarkably, these correspond to the two-zero textures of a three active neutrino mass matrix. We discuss the mass spectrum and the parameter correlations that we find in the various textures. We also present the effective mass governing neutrinoless double beta decay as a function of the lowest mass.