Signature splitting in /sup 135/Pr

In-beam spectroscopic study of /sup 135/Pr was made using 91 MeV /sup 120/Sn(/sup 19/F,4n) reaction. A strong negative parity proton band based on the h/sub 11/2/- 3/2[541] configuration with (π,α)=(-,-1/2) was observed. (-,+1/2) unfavored band is probably observed. Also two positive parity proton bands are observed and are based on the g/sub 7/2//sup +/ 3/2[422] configuration with (π,α)=(+,+-1/2). In the case of π(+) bands the backbending is caused by the alignment of two h/sub 11/2/- 3/2[541] protons. For the (-,-l/2) band the backbending is caused by the alignment of two h/sub 11/2/- protons: 3/2 [541] and 1/2[550]. This is considerably different than in /sup 134/Ce core, where the h/sub 11/2/ neutron-holes are aligning. Nuclei in the vicinity of La, Ce, Pr are predicted to be soft in γ-deformation. Ban investigation was undertaken to study the signature splitting between rotational bands in /sup 135/Pr, which is related to γ-deformation. /sup 135/Pr was produced by the /sup 120/Sn(/sup 19/F,4n) reaction at 91 MeV using the tandem accelerator at the Brookhaven National Laboratory. Coincidence data were recorded between 4 Compton-suppressed Ge detectors at -- 400 relative to the beam and 2 unsuppressed Ge detectors at -- 850. In addition an array of 11 NaI detectors around the target were used as a multiplicity selector