Microscopic aspects of shape coexistence in 72Kr and 74Kr Original Research Article

Results are presented on shape coexistence, shape transition and neutron–proton correlations at low and high spin states in the nuclei 72Kr and 74Kr. They have been obtained within the complex version of the Excited Vampir variational approach. Oblate–prolate coexistence and mixing at low spin is found to be responsible for the irregular sequence of states identified at low excitation energy. At high spins the coexistence of states with different prolate deformations results in complex multiple band structures. The present investigation indicates furthermore that particular neutron–proton matrix elements of the effective interaction play an essential role for the shape mixing.