High-precision half-life determination of $$^{14}$$ 14 O via direct $$\beta $$ β  counting

The half-life of the superallowed Fermi $$\beta ^+$$  emitter $$^{14}$$ O was determined to high precision via a direct $$\beta $$  counting experiment performed at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF. The result, $$T_{1/2}$$ ( $$^{14}$$ O) = 70619.2(76) ms, is consistent with, but is more precise than, the world average obtained from 11 previous measurements. Combining the $$^{14}$$ O half-life deduced in the present work with the previous most precise measurements of this quantity leads to a reduction in the overall uncertainty, by nearly a factor of 2. The new world average is $$T_{1/2}$$ ( $$^{14}$$ O) = 70619.6(63) ms with a reduced $$\chi ^2$$  value of 0.87 obtained from 8 degrees of freedom.