Abstract
A lower limit of 5× yr (68% confidence level) has been obtained for the half-life of the neutrinoless double beta decay of . This process would require lepton-number nonconservation and that the electron neutrino have a mass and/or the weak interaction have right-handed currents. Ge detectors of 178 and 158 were used inside a NaI active shield for 1618 h. The radioactivity background was kept so low that, despite operating above ground, there was only 2× count/keV·h total at the expected 2.041-MeV peak.
- Received 29 October 1984
DOI:https://doi.org/10.1103/PhysRevLett.54.281
©1985 American Physical Society