Abstract
The two-neutrino mode of double-beta decay in has been observed in a time-projection chamber at a half-life of )× yr (68% confidence level). This result from direct counting confirms the earlier geochemical measurements and helps provide a standard by which to test the double-beta-decay matrix elements of nuclear theory. It is the rarest natural decay process ever observed directly in the laboratory.
- Received 31 August 1987
DOI:https://doi.org/10.1103/PhysRevLett.59.2020
©1987 American Physical Society