High-precision half-life determination of ¹⁴ O via direct β counting

The half-life of the superallowed Fermi β+ emitter 14O was determined to high precision via a direct β counting experiment performed at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF. The result, T1 / 2(14O) = 70619.2(76) ms, is consistent with, but is more precise than, the world average obtained from 11 previous measurements. Combining the 14O 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 T1 / 2(14O) = 70619.6(63) ms with a reduced χ2 value of 0.87 obtained from 8 degrees of freedom.