Study of electromagnetic properties and structure of yrast bands in neutron-rich 70–76Zn isotopes

Deformation systematics of first excited 2+2+ state, the ratio of excitation energy of the 41+ and 21+ states, yrast spectra, backbending phenomena and electromagnetic quantities i.e. E2 transition probabilities and g-factors of neutron-rich 70–76Zn isotopes have been studied by employing the projected shell model approach. The theoretical results reproduce the available experimental yrast spectra, observed deformation systematics and backbending phenomena in these nuclei. The low-lying yrast states are seen to arise from zero quasiparticle band whereas the higher spin states possess multi quasiparticle structure. The calculated results predict the occurrence of second backbending in 70,72Zn and one backbending in 74,76Zn. The occurrence of backbending in these nuclei as well as the sharp changes in the calculated B(E2) transition probabilities and g  -factors confirm that there are changes in the structure of yrast bands in these nuclei. These changes are due to the occupation of different K-components of g9/2g9/2 orbit as one moves from neutron number (N)=40(N)=40 to 46. The predicted backbendings and predicted values of B(E2)s and g-factors in some of the isotopes need to be confirmed experimentally.