Search for double beta decay in 76Ge

Three possible decay modes of double beta decay are discussed. These are the two-neutrino, the neutrinoless, and the neutrinoless with boson emission modes. The theoretical implications of these modes are discussed, particularly the two exotic neutrinoless modes. The possible theoretical framework supporting the boson accompanied mode is also discussed. The measurement technique used for searching for the possible decay modes is described. The particular contaminations in a copper shield and a special lead shield are examined. The method of gathering and calibrating data is also described. The statistical methods used to analyze the resulting data sets are examined, and limits are set on the two-neutrino and neutrinoless mode decay rates. A shoulder is observed in data as would be expected for a boson accompanied decay. The possibility that this shoulder is contaminant associated is evaluated by Monte Carlo methods. A non-zero rate for the boson accompanied decay is computer based on the assumption that the observed shoulder is due to this decay mode. The rate is different from zero by several standard deviations. Possible tests to confirm or repudiate the existence of the boson accompanied decay mode are presented