Decay of ^{58}Co^{m}

We have studied some of the nuclear decay properties of $^{58}\mathrm{Co}^{m}$. The half-life is found to be ($8.853\ifmmode\pm\else\textpm\fi{}0.023$) hours, which is significantly different from the evaluations found in the literature. The absolute intensity of the 24.9-keV $\ensuremath{\gamma}$ ray emitted in the internal transition decay is ($0.0387\ifmmode\pm\else\textpm\fi{}0.0016$)%, in agreement with the calculated yield of a transition of $M3$ multipolarity. We observe $\ensuremath{\gamma}$-ray photons from a previously unreported branch for electron capture decay, with an intensity of ($0.00120\ifmmode\pm\else\textpm\fi{}0.00005$)%, consistent with expectations from the calculation of log $ft$.