Discrete Gamma-Rays at High Spin Around Mass A=156

Abstract

The nuclear structure at high spin for nuclei in the mass region around A = 156 was studied via in-beam γ-ray spectroscopy, after high spin states had been identified in heavy-ion induced reactions. For nuclei in the vicinity of the closed N = 82 shell, the levels appear as individual particle states, with large irregularities in the yrast sequence of energies and with the presence of high spin isomers. In heavier nuclei where the yrast levels exhibit a collective behavior, emphasis was put on the study of the second backbending effect.