High-spin states and band structure inSe76

High-spin states of ${}_{}{}^{76}{}_{}{}^{}\mathrm{Se}$ have been investigated through observations of $\gamma$ rays produced in the ${}_{}{}^{71}{}_{}{}^{}\mathrm{Ga}({}_{}{}^7{}_{}{}^{}\mathrm{Li}, 2n)$ reaction by bombarding an enriched ${}_{}{}^{71}{}_{}{}^{}\mathrm{Ga}$ target with 15- to 22-MeV ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ ions. Measurements were made of $\gamma$-ray singles and $\gamma -\gamma$ coincidence spectra, excitation functions, $\gamma$-ray angular distributions, $\gamma -\gamma$ angular correlations, and Doppler broadening of photopeaks. Level energies, decay modes, spins and parities, $\gamma$-ray branching ratios, $\gamma$-ray radiative admixtures, and lifetimes were deduced. There is evidence for a strongly excited quasirotational band with the highest member observed being a ${12}^{+}$ state at 5432 keV, for an odd-parity band built on a $5^{-}$ state, and for a $\Delta J=1\mathrm{}$ band which has the characteristics of a $\gamma$-vibrational band in a deformed nucleus. Interacting boson approximation model calculations are compared with the experimental results.