Half-Life ofO14

The half-life of ${\mathrm{O}}^{14}$ has been remeasured and found to be (70.91±0.04) seconds. The corresponding partial half-life for the $0^{+}$ → $0^{+}$ 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 ${\mathrm{O}}^{14}$ 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 $\mu$ 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.