Phenomenology of $keV$ sterile neutrino in minimal extended seesaw

TL;DR

This paper investigates the role of keV-scale sterile neutrinos as dark matter within a minimal extended seesaw model, analyzing their impact on neutrinoless double beta decay, baryogenesis, and neutrino mass hierarchies, with new constraints on model parameters.

Contribution

It introduces a comprehensive minimal extended seesaw framework with flavor symmetry to connect sterile neutrino dark matter, neutrinoless double beta decay, and baryogenesis, providing new bounds on parameters.

Findings

Sterile neutrino mass constrained within specific bounds for dark matter viability.

Active-sterile mixing angles are tightly bounded by neutrinoless double beta decay data.

Correlations among CP-phases, Yukawa couplings, and observable phenomena are established.

Abstract

We explore the possibility of a single generation of $keV$ scale sterile neutrino ($m_S$) as a dark matter candidate within the minimal extended seesaw (MES) framework and it's influence in neutrinoless double beta decay ($0\nu\beta\beta$) study. Three hierarchical right-handed neutrinos were considered to explain neutrino mass. We also address baryogenesis via the mechanism of thermal leptogenesis considering the decay of the lightest RH neutrino to a lepton and Higgs doublet. A generic model based on $A_4\times Z_4\times Z_3$ flavor symmetry is constructed to explain both normal and inverted hierarchy mass pattern of neutrinos. Significant results on effective neutrino masses are observed in presence of sterile mass ($m_S$) and active-sterile mixing ($\theta_{S}$) in $0\nu\beta\beta$. Results from $0\nu\beta\beta$ give stringent upper bounds on the active-sterile mixing matrix element. To establish sterile neutrino as dark matter within this model, we checked decay width and relic abundance of the sterile neutrino, which restricted sterile mass ($m_S$) within some definite bounds. Constrained regions on the CP-phases and Yukawa couplings are obtained from $0\nu\beta\beta$ and baryogenesis results. Co-relations among these observable are also established and discussed within this framework.