The HEIDELBERG-MOSCOW double beta decay experiment using enriched 76Ge

Two ways to treat the question of neutrino masses in laboratory experiments are beta and double beta decay. The authors describe the theory, experiment, and results of the Heidelberg-Moscow double beta decay experiment performed using enriched 76Ge. It is shown that by using about 10 kg of enriched material, the final goal of the Heidelberg-Moscow experiment will be a half-life limit of T1/20ν ∼ 1025y corresponding to neutrino masses down to about 0.1 eV. Thus it will be possible to check some left-right symmetric see-saw models. Further applications of enriched Ge-detectors are possible. By using enriched low-level 76Ge and 73Ge detectors, a search for dark matter can be done. In collaboration with NASA, Ge-detectors enriched in 70Ge have recently shown their potential for γ-astronomy in balloon flights. 13 refs., 3 figs., 2 tabs