High-spin states inN=50Br85andRb87nuclei

The level structures of the N=50 {sup 85}Br and {sup 87}Rb isotopes have been studied in the fission of the compound system formed in three different heavy-ion-induced reactions. In {sup 87}Rb many states above the previously known 9/2{sup +} isomer have been established. The coupling of the odd proton occupying the g{sub 9/2} orbital to the yrast states in the {sup 86}Kr core can account for the first excited states above the isomer in {sup 87}Rb. A comparison with the first excited states above the 9/2{sup +} state in {sup 85}Kr and {sup 89}Y reveals similarities in the coupling. At higher excitations similar behavior to {sup 89}Y is observed, indicating a possible presence of neutron-core excitations. In {sup 85}Br several states up to {approx}5 MeV excitation energy have been established. Two states at {approx}2 MeV excitation energy are candidates for the 9/2{sup +} state originating from the odd proton occupying the g{sub 9/2} orbital. The experimental results for both isotopes are compared with predictions of the shell model.