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

Energy spectrum of yrast band for ^(122)Cs 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 instabilityγvibration 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 previousπh11/2 vg7/2 configuration with bandhead spin I_(0)=(6^(-))which was obtained from cranked shell model(CSM)calculation,and the other one is forπh_(11/2) vh_(11/2) configuration with I_(0)=(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 thanπh_(11/2) vg_(7/2) I_(0)=(6^(-)),πh_(11/2) vh_(11/2) with I_(0)=(9^(+))is a more reasonable assignment to the yrast band in ^(122)Cs.