出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The rst evidence for neutrinoless double beta decay has been observed in
the HEIDELBERG-MOSCOW experiment, which is the most sensitive double beta decay
experiment since ten years. This is the rst evidence for lepton number violation and
proves that the neutrino is a Majorana particle. It further shows that neutrino masses
are degenerate. In addition it puts several stringent constraints on other physics beyond
the Standard Model. In particular it opens the door to test various supersymmetric
theory scenarios, for example it gives the sharpest limit on the parameter 0
111 in the
R-parity violating part of the superpotential, and gives information on the splitting of
the sneutrino-antisneutrino system. The result from the HEIDELBERG-MOSCOW experiment
is consistent with recent results from CMB investigations, with high energy
cosmic rays, with the result from the g-2 experiment and with recent theoretical work.
It is indirectly supported by the analysis of other Ge double beta experiments. Recent
criticism of various kind has been shown to be wrong, among others by measurements
with a 214Bi source (226Ra), by simulation of the background in the range of Q by
GEANT4, and by deeper investigation of statistical features such as sensitivity of peak
search, and relevance of width of window of analysis.
A Test Facility for the GENIUS project has come into operation on May 5, 2003. This
is the rst time that this novel technique for extreme background reduction in search for
rare decays is applied under the background conditions of an underground laboratory.
