New physics potential of double beta decay and dark matter search

The search for neutrinoless double beta decay and WIMP dark matter has a broad potential to test particle physics beyond the standard model. During the last years, the analysis of various contributions to the double beta decay rate by the Heidelberg group led, besides the most restrictive limit on the effective Majorana neutrino mass, to bounds on left-right-symmetric models, leptoquarks and supersymmetry. In a general framework bounds on arbitrary lepton number violating theories can be derived. Using double beta technology for direct dark matter detection, stringent limits on the spin-independent WIMP--nucleon interaction have been obtained. These results deduced from the Heidelberg-Moscow double beta decay experiment are reviewed. Also an outlook on the future of double beta decay and dark matter search, the GENIUS proposal, is given.