6533b7d4fe1ef96bd126264c

RESEARCH PRODUCT

Collective excitations in the transitional nucleiRe163andRe165

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description

Excited states in the neutron-deficient nuclei ${}_{75}^{163}{\mathrm{Re}}_{88}$ and ${}_{75}^{165}{\mathrm{Re}}_{90}$ were populated in the ${}^{106}{\mathrm{Cd}(}^{60}\mathrm{Ni},\phantom{\rule{0.16em}{0ex}}p2n\ensuremath{\gamma})$ and ${}^{92}{\mathrm{Mo}(}^{78}\mathrm{Kr}$, $3p2n\ensuremath{\gamma})$ fusion-evaporation reactions at bombarding energies of 270 and 380 MeV, respectively. \ensuremath{\gamma} rays were detected at the target position using the JUROGAM spectrometer while recoiling ions were separated in-flight by the RITU gas-filled recoil separator and implanted in the GREAT spectrometer. The energy level schemes for $^{163}\mathrm{Re}$ and $^{165}\mathrm{Re}$ were identified using recoil-decay correlation techniques. At low spin, the yrast bands of these isotopes consist of signature partner bands based on a single $\ensuremath{\pi}{h}_{11/2}$ quasiproton configuration. The bands display large energy splitting consistent with the soft triaxial shape typical of transitional nuclei above $N=82$. The configurations of the excited states are proposed within the framework of the cranked shell model.