Double Beta Decay and Nuclear Structure

Abstract

The influence of different properties of nuclear structure on nuclear matrix elements for two-neutrino and neutrinoless double beta decay is studied. We further present nuclear structure calculations for all potential 35 double beta emitters with A ≥ 70. New and more stringent limits on the neutrino mass are deduced from existing double beta decay experiments. It is found that two-neutrino decay is strongly influenced by pairing as well as by various long-range forces. Neutrinoless decay on the other hand is found to be determined mainly by pairing, allowing more reliable predictions for this decay mode. As a consequence of the different effects of the long-range forces on the matrix elements the often-used “scaling procedure” leads to overestimates of the neutrino mass. It is discussed to what extent interference between different neutrinos affects the obtained mass limits.