The nuclei ${}^{131}\mathrm{I}$ and ${}^{133}\mathrm{I}$ have been populated in multinucleon transfer reactions between ${}^{136}\mathrm{Xe}$ ions and various targets, and their structure has been investigated by time-correlated $\gamma$-ray coincidence spectroscopy and the measurement of $\gamma$-ray angular correlations. A $19/2^{-}$ isomer at 1918 keV, with a half-life of 24(1) μs, has been identified in ${}^{131}\mathrm{I}$, as well as nanosecond isomers with $J^{\pi }=23/2^{+}$ in both isotopes. A $T_{1/2}=25(3)$ ns isomer at 4308 keV in ${}^{131}\mathrm{I}$ is suggested to have $J^{\pi }=(31/2^{-},33/2^{-})$ and is primarily attributed to the coupling of an odd proton in the $d_{5/2}$ or $g_{7/2}$ orbit with the $({\pi }^2){}_{0^{+}}(\nu h_{11/2}^{-3}{d}_{3/2}^{-1}){}_{{15}^{-}}$ configuration in ${}^{130}\mathrm{Te}$ responsible for the ${15}^{-}$ isomer in that nucleus. The observed level properties are compared with predictions of a shell-model calculation.

• Received 15 April 2009

DOI:https://doi.org/10.1103/PhysRevC.79.064311