Test and predict neutrinoless double-beta decay with other observables

Predictions of neutrinoless double-beta decay (0nbb) nuclear matrix

elements are challenging, and markedly differ from each other when

different many-body methods are used. One possible avenue to improve

this current status is to use data from other observables related to

0nbb to test the theoretical calculations, and to use correlations of

these observables with 0nbb matrix elements to predict them more

confidently. In my talk I will present recent work focused on using

nuclear spectroscopy data to test calculations and double-gamma and

two-neutrino double-beta decays to predict 0nbb nuclear matrix

elements.