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

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.