The structure of the deformed, doubly odd nuclide ${}^{180}\mathrm{Re}$ has been studied by γ-ray and conversion-electron spectroscopy using the ${}^{174}\mathrm{Yb}$(${}^{11}\mathrm{B}$,5n) reaction with a pulsed 71 MeV beam of ${}^{11}\mathrm{B}$ ions. Several of the previously known intrinsic states have been given revised spin and parity assignments. Rotational bands are observed with $K^{\pi }=(4^{+}),(5^{-}),(7^{+}),8^{+},9^{-},{13}^{+},{14}^{-},{15}^{-},{16}^{+},{21}^{-}$, and $({22}^{+}$). Among these, a four-quasiparticle t band is identified, which is already energetically favored at its bandhead compared to the corresponding two-quasiparticle band; and two six-quasiparticle bands are identified and associated with a $\tau =13$ μs isomer. The observed structures, including g factors and alignments, are interpreted with the aid of Nilsson-plus-BCS calculations and configuration-constrained potential energy surface calculations. Reduced-hindrance values are obtained for K-forbidden transitions, illustrating the important role of the K quantum number for near-yrast isomers.

• Received 1 August 2005

DOI:https://doi.org/10.1103/PhysRevC.72.054306