High-spin states in the doubly odd $Z=77$ nucleus ${}^{188}\mathrm{Ir}$ were studied using the reaction ${}^{186}\mathrm{W}$(${}^7\mathrm{Li}$, $5n$) at 59 MeV and the GASP spectrometer for γ-ray detection. The level structures recently suggested to be built on the known 4.1(3) ms isomeric state of this nucleus have been considerably revised and extended and an isomer with a lifetime of 17.7(2) ns has been identified within the main decay sequence. In addition two rotational bands built on low spin states below the ms isomer have been observed for the first time. The basic features of the excitation scheme of ${}^{188}\mathrm{Ir}$ are discussed within the Hartree-Fock-Bogoliubov theory within the Lipkin-Nogami approach with the finite-range density-dependent Gogny force.

• Received 9 April 2006

DOI:https://doi.org/10.1103/PhysRevC.77.024310