The stable nucleus ${}^{177}$Hf was studied with time-correlated particle-$\gamma$-$\gamma$ techniques following the reaction ${}^{176}\mathrm{Yb}{(}^9\mathrm{Be},\alpha {4n)}^{177}$Hf at a beam energy of 70 MeV. New high-spin states include extensions to three-quasiparticle bands based on the $K^{\pi }{=23/2\mathrm{}}^{+}$ and ${25/2}^{-}$ configurations, together with a new band associated with the $K^{\pi }{=19/2\mathrm{}}^{-}$, $T_{1/2}=56\mathrm{}$ μs isomer. Moreover, the band based on the five-quasiparticle $T_{1/2}$=51 minute, $K^{\pi }{=37/2\mathrm{}}^{-}$ state has been found, and a band assigned to a new $K^{\pi }{=39/2\mathrm{}}^{+}$, five-quasiparticle state. Values of ${(g}_K-g_R{)/Q}_0$ agree well with the configuration assignments made to new and previously known bands. Comparison with multiquasiparticle calculations that incorporate a Lipkin-Nogami treatment of pairing correlations with blocking, suggests that all of the most favored three- and five-quasiparticle states have been observed. The dependence of the $\gamma$-ray intensities on the angular yields of the $\alpha$ particles suggests that the population arises from two entry distributions: one associated with complete fusion of the beam with the target, the other with incomplete fusion.

• Received 20 April 1998

DOI:https://doi.org/10.1103/PhysRevC.58.831