Three-quasiparticle rotational bands in 101Rh: IBFBPM description and signature inversion of the πg9/2 orbital

Abstract

High- and intermediate-spin level structures of the 101Rh nucleus have been studied using the reaction 70Zn+ 36S at 130 MeV bombarding energy. γ-rays were detected with the EUROGAM II detector array. Three new ΔI=1 rotational bands have been observed in this nucleus. The deduced level scheme is compared with results of calculations using Interacting Boson–Fermion plus Broken Pair Model. The model calculations give a consistent description of the one- and three-quasiparticle states providing fair agreement between the observed and calculated level energies and branching ratios. Experimental Routhians of the new high-spin bands and the πg 9/2 νh 11/2 bands in the neighbouring Rh and Ag nuclei have been found to exhibit signature inversion. This signature inversion can be interpreted qualitatively as the inversion of the two signatures of the proton g 9/2 orbital caused by triaxial nuclear shape with large positive γ parameter.