Neutron-deficient ${}_{}{}^{127}{}_{}{}^{}\mathrm{Ba}$ has been formed through the positron decay of its precursor ${}_{}{}^{127}{}_{}{}^{}\mathrm{La}$ produced by the ${}_{}{}^{115}{}_{}{}^{}\mathrm{In}({}_{}{}^{16}{}_{}{}^{}\mathrm{O}, 4n){}_{}{}^{127}{}_{}{}^{}\mathrm{La}$ reaction. The $\gamma$-ray spectra have been studied using thin window intrinsic Ge and large volume Ge(Li) detectors. In contrast to the results reported earlier, $\gamma$ rays of energies (relative intensities) 66.0 (22 ± 2), 72.7 (9 ± 1), 114.8 (85 ± 5), 180.8 (100), 567.5 (2.9 ± 0.3), 577.6 (4.0 ± 0.4), 626.0 (2.2 ± 0.2), 682.0 (2.5 ± 0.3), 692.5 (2.8 ± 0.3), 1087.0 (4.4 ± 0.4), and 1203.0 (20 ± 2) keV have been observed to be associated with the decay of ${}_{}{}^{127}{}_{}{}^{}\mathrm{Ba}$. The half-life of ${}_{}{}^{127}{}_{}{}^{}\mathrm{Ba}$ has been established as 13.0 ± 0.5 min by following the decay of the photopeaks of intense $\gamma$ rays. The $\gamma -\gamma$ coincidence spectra were studied using two Ge(Li) detectors and a two parameter analyzer system. A revised decay scheme is proposed.

RADIOACTIVITY ${}_{}{}^{127}{}_{}{}^{}\mathrm{Ba}$ [from ${}_{}{}^{115}{}_{}{}^{}\mathrm{In}({}_{}{}^{16}{}_{}{}^{}\mathrm{O}, 4n){}_{}{}^{127}{}_{}{}^{}\mathrm{La}\stackrel{{\beta }^{+}\mathrm{EC}}{\to }{}_{}{}^{127}{}_{}{}^{}\mathrm{Ba}$]; measured $T_{\frac{1}{2}}$, $E_{\gamma }$, $I_{\gamma }$, $\gamma \gamma$ coinc; deduced ${}_{}{}^{127}{}_{}{}^{}\mathrm{Cs}$ levels, $J^{\pi }$; Ge(Li) and intrinsic Ge detectors.

• Received 18 November 1974

DOI:https://doi.org/10.1103/PhysRevC.11.1762