Impact of an eV-mass sterile neutrino on the neutrinoless double-beta decays: A Bayesian analysis

Abstract

To quantitatively assess the impact of an eV-mass sterile neutrino on the neutrinoless double-beta (0νββ) decays, we calculate the posterior probability distribution of the relevant effective neutrino mass |mee′| in the (3+1)ν mixing scenario, following the Bayesian statistical approach. The latest global-fit analysis of neutrino oscillation data, the cosmological bound on the sum of three active neutrino masses from Planck, and the constraints from current 0νββ decay experiments are taken into account in our calculations. Based on the resultant posterior distributions, we find that the average value of the effective neutrino mass is shifted from |mee|‾=3.37×10−3eV (or 7.71×10−3eV) in the standard 3ν mixing scenario to |mee′|‾=2.54×10−2eV (or 2.56×10−2eV) in the (3+1)ν mixing scenario, with the logarithmically uniform prior on the lightest neutrino mass (or on the sum of three active neutrino masses). Therefore, a null signal from the future 0νββ decay experiment with a sensitivity to |mee|≈O(10−2)eV will be able to set a very stringent constraint on the sterile neutrino mass and the active-sterile mixing angle.