Neutrinoless Double Beta Decay and Light Sterile Neutrino

Abstract

The recent neutrino experiment results show a preference on normal mass ordering of neutrinos. The global efforts to search for neutrinoless double beta decays undergo a broad gap with the approach to the prediction in three-neutrino framework based on the normal ordering. Current research is to show that it is possible to find a neutrinoless double beta decay signal even with normal ordered neutrino masses. We propose the existence of light sterile neutrino as a solution to the higher effective mass of electron neutrino expected by experiments under operation. A few short-baseline oscillation experiments gave rise to exclusion bound to the mass of sterile neutrino and its mixing with the lightest neutrino. It is demonstrated that results of neutrinoless double beta decays can also narrow down the ranges of the mass and the mixing angle of sterile neutrino.