New limits on neutrino masses and right-handed currents from double beta decay

Data obtained for different time periods from 4, 6, and 8 Ge detectors in an active NaI shield yield a maximum likelihood 68% C.L. lower limit of 3.9x1023yr for the half-life of the 0+→0+ transition, and 1.5x1023yr for the 0+→2+ transition, for zero-neutrino double beta decay of 76Ge. They also set 90% C.L. lower limit of 8x1019yr for the two-neutrino decay, and 6x1020yr for the mode in which a light boson (Majoron) is emitted with no neutrinos. These results are used to set limits on light and very heavy neutrino masses, on Majoron-neutrino coupling, and on right-handed currents. (orig.)