${}_{}{}^{84}{}_{}{}^{}\mathrm{Sr}$ has been investigated by means of conventional in-beam gamma-ray spectroscopy with the reactions ${}_{}{}^{76}{}_{}{}^{}\mathrm{Ge}$(${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$,$4n$) and ${}_{}{}^{81}{}_{}{}^{}\mathrm{Br}$(${}_{}{}^6{}_{}{}^{}\mathrm{Li}$,$3n$). Lifetimes of 10 levels have been measured by the recoil distance Doppler shift technique. Four positive and at least two negative parity bands have been found. The energies of the ground state band and quasigamma band as well as the $E2\mathrm{}$ transition strengths are compared with theoretical values obtained from the proton-neutron interacting boson model. A relatively long lived $8^{+}$ state has been found, to which we assign the ${\left(\nu g_{\frac{9}{2}}\right)}^{-2\mathrm{}}$ configuration.

NUCLEAR REACTIONS ${}_{}{}^{76}{}_{}{}^{}\mathrm{Ge}$(${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$,$4n\gamma$), $E=48-60\mathrm{}$ MeV; ${}_{}{}^{81}{}_{}{}^{}\mathrm{Br}$(${}_{}{}^6{}_{}{}^{}\mathrm{Li}$,$3n\gamma$), $E=19-32\mathrm{}$ MeV, measured $E_{\gamma }$, $I_{\gamma }$, $\gamma \gamma$ coincidence, $\gamma$ angular distribution, recoil distance Doppler shift; ${}_{}{}^{84}{}_{}{}^{}\mathrm{Sr}$ deduced levels, $J$, $\pi$, $\tau$. Enriched targets, Ge(Li) detectors.

• Received 26 June 1981

DOI:https://doi.org/10.1103/PhysRevC.25.226