SEARCH FOR NEW PHYSICS WITH NEUTRINOLESS DOUBLE-BETA DECAY

Neutrinoless double beta decay (0 nu beta beta) is one of the most sen sitive approaches to test particle physics beyond the standard model. During the last years, besides the most restrictive limit on the effec tive Majorana neutrino mass, the analysis of new contributions by the Heidelberg group led to bounds on left-right-symmetric models, leptoqu arks and R-parity violating models competitive to recent accelerator l imits, which are of special interest in view of the HERA anomaly at la rge Q(2) and x. These new results deduced from the Heidelberg-Moscow d ouble beta decay experiment are reviewed. Also an outlook on the futur e of double beta decay, the GENIUS proposal, is given.