KeV dark matter in minimal extended seesaw model and its predictions in neutrinoless double beta decay and baryogenesis

TL;DR

This paper presents a minimal extended seesaw model with specific symmetries that predicts neutrino properties, explores keV sterile neutrino dark matter, and examines implications for neutrinoless double beta decay and baryogenesis.

Contribution

It introduces a novel symmetry-extended minimal seesaw model that successfully predicts neutrino mixing parameters and explores its phenomenological implications for dark matter and baryogenesis.

Findings

Predicts neutrino mixing angles consistent with experimental data

Provides bounds on effective neutrino mass and sum of neutrino masses

Suggests the model favors normal hierarchy over inverted hierarchy

Abstract

We develop an $A_4 \times Z_4 \times Z_2$ symmetry extension of Standard Model under the minimal extended seesaw (MES) mechanism which successfully predicts neutrino masses and mixings patterns. This model breaks $\mu-\tau$ symmetry of neutrino mass matrix and explains leptonic mixing with non-zero $\theta_{13}$. We study the phenomenological results of the keV-scale sterile neutrino as a dark matter candidate along with other phenomenologies such as neutrino oscillation observables, neutrinoless double beta decay, baryogenesis via leptogenesis, etc. Dirac CP-violating phase $\delta_{CP}$ and two Majorana phases $\alpha$ and $\beta$ are also calculated from the leptonic mixing matrix. Best-fit values of the model parameters and neutrino observables are calculated from $\chi^2$ analysis. The model predicts best-fit values of neutrino mixing angles to be $\sin^2\theta_{23}=0.555,\ \sin^2\theta_{12}=0.301$ and $\sin^2\theta_{13}=0.022$ for normal hierarchy. Significant results consistent with experimental data are also observed for effective neutrino mass $m_{\beta\beta} \sim (0.97 - 5.02)$ meV, effective electron mass $m_{\beta} \sim (0.084-0.41)$eV and sum of active neutrino masses $\sum m_{i} < 0.12$ eV. The model does not favour Inverted hierarchy at the 3$\sigma$ level with the given parameter space.