Shape coexistence in ^96,98Sr

The structure of neutron-rich ^96,98Sr isotopes was investigated by low-energy Coulomb excitation of radioactive beams at the REX-ISOLDE facility. Reduced transition probabilities and spectroscopic quadrupole moments were extracted from the differential Coulomb excitation cross sections. These results allow for the first time to draw definite conclusions about the shape coexistence of highly deformed prolate and spherical configurations. In particular, a very small mixing between the coexisting states is observed, contrary to other mass regions where strong mixing is the rule. The experimental data suggest a significant contribution of the triaxial degree of freedom in the ground state of both isotopes. In addition, experimental information on low-lying states in ⁹⁸Rb has been obtained. This document is made up of an abstract and the slides of the presentation. (authors)