The half-life of 14O and the ft value of the superallowed Fermi decay

Abstract

A series of experiments has been carried out to measure the half-life for 14O decay, using different reactions and a variety of techniques, in two laboratories. Considerable care has been taken in the experiments, and in the data analyses, to reduce the possibility of systematic errors. The final result obtained is 70.588 ± 0.028 s, where the error is the statistical standard deviation (external error) of the weighted mean. This leads to an ft value for the 0 + → 0 + superallowed 14O Fermi decay of 3050 ± 11 s, excluding electromagnetic radiative corrections; the corresponding “effective” ft value is 3090 ± 11 s, allowing for the first-order outer radiative correction. The error quoted for the ft value is determined very largely by the error in the f-value. This result for the 14O Fermi decay is consistent with the ft values for the 26mAl and 34Cl decays.