High spin states inKr75: Approaching superdeformation in theA=80region

Abstract

Excited states in ${}_{}{}^{75}{}_{}{}^{}\mathrm{Kr}$ were populated via the reaction ${}_{}{}^{46}{}_{}{}^{}\mathrm{S}$,2pn) at a beam energy of 97 MeV. Several new high-spin states were found. Evidence for band crossings was found in both the positive- and negative-parity bands. Calculations using a cranked Strutinsky-Bogolyubov model with a Woods-Saxon potential indicate noticeably different deformations for the opposite parity bands: ${\beta }_2$=0.40, γ=-8° for the positive-parity band and ${\beta }_2$=0.36, γ=3° for the negative-parity band. These deformations are comparable to superdeformations reported by other authors in the cerium region. Signature splitting in both positive- and negative-parity bands was well reproduced by the calculations. Indirect evidence suggests shape coexistence within the positive-parity band at low spin.