Coexistence of the core excited states in 58Ni

Abstract

In a shell model calculation of the low-lying states in 58Ni, 3p-1h and 4p-2h configurations are taken into account together With the two particle configurations in the 1p 3 2 , 0f 5 2 and 1p 1 2 orbits outside the 56Ni core. In order to truncate the three particle and four particle configurations, we employ the pseudo SU(3) coupling scheme which is supposed to be suitable for the description of the collective rotational character. To explain the enhanced E2 transition from the first 2 + state to the ground state, a nucleon effective charge of 1.05 e is needed, which is consistent with the value calculated based using perturbation theory. The spectroscopic factors of the α-transfer reaction are also calculated and compared with the recent observed values.