Coulomb excitation of 78Kr

The Kr isotopes are considered to be among the best cases for shape coexistence studies in the mass A∼70 region. Our campaign to investigate in detail the development of the shape coexistence in the neutron deficient Kr isotopes was started with the stable nucleus 78Kr. To obtain the information about the intrinsic shape, Coulomb excitation experiments were performed. A total of 26 matrix elements were determined for 78Kr. Simple geometrical and algebraic models do not reproduce all details of the electromagnetic structure. A good interpretation of the complex structure of the nucleus with competing oblate and prolate shapes comes from a study within the complex EXCITED VAMPIR approximation using Hartree–Fock–Bogoliubov transformations with symmetry projection before variation. The measured matrix elements are compared with the predictions of this model.