An A4 Model for keV-Scale Sterile Neutrino Dark Matter

Abstract

We develop an A4 × Z4 × Z2 symmetry model of neutrino masses and mixings within the minimal extended seesaw mechanism where three right-handed neutrinos νR1, νR2, and νR3 and a keV-scale singlet sterile neutrino S are added to the Standard Model. This model breaks μ-τ symmetry of the neutrino mass matrix and successfully explains leptonic mixing with nonzero θ13.We study the phenomenological results of the keV-scale sterile neutrino as a dark matter candidate by calculating the relic abundance and its decay rate to active neutrinos. Significant results are also observed for solar and atmospheric mixing angles within the 3σ bounds, sum of the active neutrino masses (Σmi < 0.12 eV), and effective neutrino mass from neutrinoless double beta decay, meff ∼ (0.001174–0.004367) eV for NH and meff ∼ (0.04766–0.05088) eV for IH.

Keywords

• Sterile neutrino, Dark matter, A4 model, Beyond standard model