Excited states in the stable nucleus ${}^{193}\mathrm{Ir}$ have been investigated through an in-beam $\gamma$-ray spectroscopic technique following the ${}^{192}\mathrm{Os}$(${}^7\mathrm{Li}$, $\alpha 2n$) reaction at a beam energy of 44 MeV. A level scheme built on the $\pi h_{11/2}$ isomer has been extended to high-spin states using eleven newly observed $\gamma$ transitions. The $\pi h_{11/2}$ band is proposed to be formed by coupling an $h_{11/2}$ proton to a core with large triaxial deformation. Three-quasiparticle states are suggested in ${}^{193}\mathrm{Ir}$ on referring to the similar states in ${}^{187}\mathrm{Ir}$. The features of signature splitting in the $\pi h_{11/2}$ bands of ${}^{187-193}$Ir are discussed with the help of total Routhian surface calculations.

• Received 16 March 2011

DOI:https://doi.org/10.1103/PhysRevC.83.054323