Configuration and Spin Assignments of Yrast Band for Doubly Odd Nucleus 122Cs

Abstract

Energy spectrum of yrast band for 122Cs is studied by using particle-rotor model (PRM) of odd-odd nuclei, in which special attention is paid to the model basis accounting for the effect of the instability γ vibration perturbation around axial symmetry. In order to check the assignments of this band, two calculation schemes are put into practice. The first one is for previous πh11/2 ⊗ νg7/2 configuration with bandhead spin I0 = (6-) which was obtained from cranked shell model (CSM) calculation, and the other one is for πh11/2 ⊗ νh11/2 configuration with I0 = (9+) supported by the systematic analyses of experimental data. A qualitative comparison between the present PRM calculation and that of CSM has also been made. The results indicate that, rather than πh11/2 ⊗ νg7/2 with I0 = (6-), πh11/2 ⊗ νh11/2 with I0 = (9+) is a more reasonable assignment to the yrast band in 122Cs.