Predictions for neutrinoless double-beta decay in the 3+1 sterile neutrino scenario

We present accurate predictions of the effective Majorana mass vertical bar m beta beta vertical bar in neutrinoless double-beta decay in the standard case of 3v mixing and in the case of 3+1 neutrino mixing indicated by the reactor, Gallium and LSND anomalies. We have taken into account the uncertainties of the neutrino mixing parameters determined by oscillation experiments. It is shown that the predictions for vertical bar m beta beta vertical bar in the cases of 3v and 3+1 mixing are quite different, in agreement with previous discussions in the literature, and that future measurements of neutrinoless double-beta decay and of the effective light neutrino mass in beta decay or the total mass of the three lightest neutrinos in cosmological experiments may distinguish the 3v and 3+1 cases if the mass ordering is determined by oscillation experiments. We also present a relatively simple method to determine the minimum value of vertical bar m beta beta vertical bar in the general case of N-neutrino mixing.