Validity of quasi-degenerate neutrino mass models and their predictions on baryogenesis

TL;DR

This paper investigates quasi-degenerate neutrino mass models with CP-phases, analyzing their compatibility with current neutrino data and their implications for baryogenesis via leptogenesis, favoring the normal hierarchy pattern.

Contribution

It provides a detailed analysis of QDN models with CP-phases under $$ symmetry, predicting neutrino parameters and baryon asymmetry, highlighting the normal hierarchy as more favorable.

Findings

Predicted neutrino parameters align with experimental data.

QDN models can explain baryon asymmetry through leptogenesis.

Normal hierarchy pattern is more consistent with observations.

Abstract

Quasi-degenerate neutrino mass models (QDN) which can explain the current data on neutrino masses and mixings,are studied. In the first part, we study the effect of CP-phases on QDN mass matrix obeying $\mu-\tau$ symmetry in normal hierarchical (QD-NH) and inverted hierarchical (QD-IH) patterns.The numerical predictions are consistent with observed data on solar mixing angle, absolute neutrino mass parameter consistent with neutrinoless double beta decay mass parameter and sum of three absolute neutrino masses from cosmological bound.The neutrino mass matrix is parameterized using only two unknown parameters. The second part deals with the estimation of observed baryon asymmetry of the universe. The prediction is nearly consistent with observation with flavoured thermal leptogenesis scenario. QD-NH model appears to be more favourable than those of QD-IH models.The present analysis shows that the three absolute neutrino masses may exhibit quasi-degenerate pattern in nature. They are far from discrimination at the moment.