High spin states and evidence for octupole correlations in 117Xe

High-spin states of Xe-117 were investigated by means of in-beam gamma-ray spectroscopic techniques via the reaction of Si-28 bombarding: a Mo-92 target at beam energies of 100-120 MeV. A positive-parity rotational band decaying into the yr ast negative-parity band by a series of enhanced El transitions Tvas observed for the first time, implying the existence of octupole correlations in Xe-117. The B(E1) values increase with spin. The nu d(5/2) band mas firmly established up to 27/2(+) and the B(M1)/B(E2) ratios were extracted from the relative intensities of gamma-rays in this band. The previously known nu h(11/2) and nu g(7/2) [413]5/2(+) alpha = -1/2 bands were confirmed and extended up to high spins and two bandcrossings are observed in the latter at (h) over bar omega=0.33 and 0.44 MeV, respectively. The bandcrossings and configurations of these bands are discussed by TRS and CSM calculations. In a gamma-gamma-t measurement, the 11/2(-) and 7/2(-) levels were identified as two isomers with half-lives of 59.4+/-20 ns and 16.5+/-8.0 ns, respectively.