Double beta decay, neutrino mass and nuclear structure

The status of the understanding of nuclear structure effects on matrix elements for double beta decay of neutron-rich nuclei is reviewed. 2 nu and 0 nu beta beta -decay rates for all potential beta beta -emitters with A>70 are predicted. The dependence on different effective interactions and their renormalization is discussed. It results that neutrinoless double beta decay remains the most powerful tool for investigating the electron neutrino mass. The status and perspectives of a second-generation experiment using enriched 76Ge (Heidelberg-Moscow cooperation) are briefly presented.