Evolution of collectivity and shape transition in Zn 66

Abstract

Excited states in Zn66 were investigated through the in-beam ?-ray spectroscopic techniques using the Cr52(O18, 2p2n) fusion-evaporation reaction at a beam energy of 72.5 MeV. The ?-rays emitted by the de-exciting nuclei were recorded in coincidence mode using the 14 Compton suppressed Ge clover detectors of the Indian National Gamma Array. With 14 new transitions being identified, the level scheme of Zn66 has been extended up to the excitation energy ˜12.3MeV and spin ˜17?. A rotational band, associated with the two quasineutrons from the 1g9/2 orbital, has been found to exhibit a band crossing with the ground-state band at a spin of 6?. The evolution of the collectivity and shape transition in this nucleus have been discussed in the framework of the total Routhian surface calculations and in comparison with the neighboring Ge68,70 nuclei. © 2020 American Physical Society.