Large scale nuclear structure calculations for medium mass N=Z nuclei

摘要

Results are presented on shape coexistence and neutron-proton correlations at low and high spin states in medium mass N=Z nuclei. They have been obtained within the complex version of the Excited Vampir variational approach. Oblate-prolate coexistence and mixing at low and intermediate spins is found to be responsible for the irregular sequence of states identified at low excitation energy in the nuclei Kr-72 and Se-68. At high spins the coexistence of states with different prolate deformations results in complex multiple band structures. The spherical-deformed coexistence identified in the nucleus Ni-56 is described using a rather large model space. The reported investigations indicate that particular neutron-proton matrix elements of the effective interaction could influence the relative position of the oblate and prolate configurations as well as of the almost spherical configurations and the deformed ones and consequently play an essential role for the shape mixing. [References: 16]