Abstract
The half-life of due to multichannel weak decay 2EC, and has been determined for the first time by the measurement of the daughter accumulated in natural barite from the Belorechenskoe deposit in North Caucasus, Russia. The accumulation time was determined from U-Xe and K-Ar gas-retention ages measured in the same material, yielding a half-life for for all weak decay modes of (68% C.L.), about a factor of 2 lower than that predicted by the proton-neutron quasiparticle random phase approximation. From excess observed in this barite, the half-life for weak decay of can be estimated However, this value is more tentative, since other sources of this isotope cannot be excluded, but the lower limit of remains firm.
- Received 18 April 2001
DOI:https://doi.org/10.1103/PhysRevC.64.035205
©2001 American Physical Society