Abstract
The half-life of has been remeasured and found to be (70.91±0.04) seconds. The corresponding partial half-life for the → beta transition is found to be (71.34±0.08) seconds. These results are about 1.6% less than reported earlier. The new half-life is combined with the end-point energy as recently determined by Bardin et al. to re-evaluate the Fermi coupling constant for beta decay. From this, the mean life of the meson is calculated. The predicted mean life is greater than the observed value by (3.3±0.4)% if the radiative corrections of Kinoshita and Sirlin are used, and by (1.4±0.4)% if the radiative corrections of Durand et al. are used.
- Received 26 September 1960
DOI:https://doi.org/10.1103/PhysRev.121.846
©1961 American Physical Society