Understanding the Masses and Mixings of One-Zero Textures in 3+1 Scenario

TL;DR

This paper analyzes one-zero textures in the neutrino mass matrix within a 3+1 scenario, exploring sterile neutrino mixing and phenomenological implications for different mass spectra, advancing understanding of neutrino mass structures.

Contribution

It provides a comprehensive analysis of allowed one-zero textures in the 3+1 neutrino framework, detailing their phenomenological consequences and sterile mixing correlations.

Findings

Seven viable textures with one-zero in hierarchical spectrum.

Eight viable textures with one-zero in quasi-degenerate spectrum.

Implications for effective Majorana mass and sterile mixing parameters.

Abstract

We present a detailed analysis and phenomenological consequences of neutrino mass matrix, $M_{\nu}$, with one-zero texture in the flavor basis where the active neutrino sector is extended by one sterile neutrino (3+1 case). In particular, our aim is to explore behaviour of the sterile mixing parameters in detail when one of the elements of the neutrino mass matrix goes to zero. To study this, we consider two distinct mass spectrum of the active neutrinos: (i) completely hierarchical mass spectrum with a vanishing neutrino mass and (ii) completely quasidegenerate mass spectrum. In 3+1 scenario, the low energy neutrino mass matrix, $M_{\nu}$, is a $4 \times 4$ matrix and has 10 independent elements. Thus it can have 10 possible one-zero textures. From the earlier studies it can be inferred that, if one assumes one vanishing neutrino mass, then only seven of these $M_{\nu}$ are phenomenologically allowed by the current neutrino oscillation data. On the other hand, if the neutrinos are quasidegenerate then there are eight phenomenologically viable one-zero textures. In this present work, we study the correlations between the sterile mixing parameters for each of these allowed textures for both mass spectrum and also their implications on the effective Majorana mass.