Lifetime measurement of high spin states in non-yrast bands in ¹⁷⁷Re*

Abstract The deformation driving tendency of various single particle orbitals near the Fermi surface has been investigated with the lifetime measurements of high spin states in the non-yrast bands of nucleus. For this study, the ( , 4n ) reaction at a beam energy of 84 MeV was used. Lifetimes of four lowest levels in the band and four levels in the ( α = –1/2) band were measured. The extracted transition quadrupole moments for the intruder band showed a sharp increase with increasing level spin, indicating a significant shape transition in the nucleus. The average transitional quadrupole moment ( ), a measure of deformation, for the band was significantly larger ( ~ 8.7 (6) eb) compared with the ( ~ 6.3 (5) eb) band. To interpret the observed shape changes in the two bands, the experimental transition probabilities for these bands were compared with the results obtained from Projected Shell Model (PSM) calculations.