New expectations and uncertainties on neutrinoless double beta decay

The hypothesis that the Majorana mass of ordinary neutrinos dominates the rate of neutrinoless double beta decay is investigated. Predictions from neutrino oscillations are updated. Nuclear uncertainties are discussed, evaluating the impact of the quenching of the axial vector coupling constant in the nuclear medium, recently pointed out by Iachello et al. [Phys. Rev. C 87, 014315 (2013)]. Also, the sensitivity of present and future experiments is assessed, and possible implications of the knowledge on neutrino masses from cosmology are studied. The predictions from neutrino oscillations are compared with the results from cosmology and from neutrinoless double beta decay searches, emphasizing the important role of the measurement errors. The obstacles to an experimental determination of the Majorana phases are pointed out.