STATUS OF THE HEIDELBERG-MOSCOW BETA-BETA-EXPERIMENT WITH GE-76

The status of the HEIDELBERG-MOSCOW double beta decay experiment using 16.9 kg of 86% enriched Ge-76 is presented. From this material 12 kg are available in form of five grown crystals. Three detectors with a total mass of 6.02 kg are in regular operation in the GRAN SASSO underground laboratory. With a total Ge-76 exposure of 91.63 mol.y we derive the following half life limits for the neutrinoless double beta (0nubetabeta) decay: T1/2 (0+ --> 0+) > 1.9.10(24) y and T1/2 (0+ --> 2+) > 8.2.10(23) y with 90% C.L. In the transition to the ground state a stagnation of the half life limit in time is visible. By this limit a Majorana mass of the neutrinos larger than 1.1 eV is excluded. The background at 2 MeV is B = 0.3 counts/kg.y.keV for the total array. From the data taken with the second enriched detector a half life of T1/2 = (1.42 +/- 0.03 stat +/- 0.13 syst). 10(21) y for the two neutrino double beta (2nubetabeta) decay of Ge-76 is extracted. This result represents with an Ge-76 exposure of 19.3 mol.y the first high statistics measurement of this rare nuclear decay mode. From the same set of data a half life of 1.7.10(22) y is excluded for the neutrinoless decay with majoron emission (0nuchibetabeta), leading to an upper limit for the neutrino-majoron coupling of <g(nuchi) > < 1.8-10(-4) with 90% C.L.