The half-life of the T=(3/2 nucleus ${}_{}{}^{13}{}_{}{}^{}\mathrm{O}$ has been remeasured to be $T_{1/2}$=(8.55±0.05) ms by observing a time spectrum of β-delayed protons. This value is appreciably smaller than previously reported. Branching ratios of the β transitions to the ground and excited states of ${}_{}{}^{13}{}_{}{}^{}\mathrm{N}$ have been obtained from the proton energy spectrum and the proton-to-β intensity ratio. Mirror asymmetry in the ft value deduced for the ground-state transition is found to be consistent with the theoretical estimate which takes account of nuclear asymmetry due to the Coulomb interaction.

• Received 24 August 1989

DOI:https://doi.org/10.1103/PhysRevC.41.358