Challenges for a reliable shell model description of the neutrinoless double beta decay matrix elements

Abstract

Assuming that the neutrinos are Majorana particles and the neutrinoless double beta (0νββ) decay is observed, a reliable 0νββ matrix element is necessary to decide the neutrino mass hierarchy and the minimum neutrino mass. Many nuclear structure techniques, including the shell model, are presently used to calculate these matrix elements. In the last few years one could see a slow convergence of these results, but not yet at a level of 20 several shell model effective interactions and varying other parameters, finding results in a range that spans about 20In this contribution we describe challenges for obtaining reliable shell model 0νββ matrix elements, with emphasis to 76Ge and 82Se decays.