No abstract

No abstract

High-spin states in 124 Ba were investigated in two experiments using the 64 Ni( 64 Ni,4n) 124 Ba reaction at three different beam energies. In-beam γ-ray coincidences were measured with the Euroball and Gammasphere detector arrays, respectively. In the experiment with Euroball, the CsI detector array Diamant was employed to discriminate against charged-particle channels. Six new rotational bands were observed in 124 Ba and previously known bands were extended to higher spins and in some cases also in the low-spin region. One of the bands shows a transition from collective to non-collective behavior at high spins. Configuration assignments are suggested on the basis of comparison with cranked shell model and cranked Nilsson-Strutinsky calculations.

The γ decay of the nuclei 124,125 Ba has been investigated by means of the EUROBALL spectrometer, coupled to the DIAMANT array of charged-particle detectors, using the reaction 64 Ni + 64 Ni at E beam = 255 and 261 MeV. In the nucleus 125 Ba six new E1 transitions have been found to link opposite-parity bands currently interpreted as νd 5/2 (+g 7/2 ), νh 11/2 structures. The previously unknown J π = 3 − level in the nucleus 124 Ba has also been identified; its excitation energy is accurately reproduced by a microscopic calculation including octupole correlations. Both issues are bolstered by sizable B(E1)/B(E2) ratios.