Low-energy Coulomb excitation of 96,98Sr beams
Phys. Rev. C
The structure of neutron-rich
96,98
Sr
nuclei was investigated by low-energy safe Coulomb excitation of radioactive beams at the REX-ISOLDE facility, CERN, with the MINIBALL spectrometer. A rich set of transitional and diagonal 𝐸2 matrix elements, including those for non-yrast structures, has been extracted from the differential Coulomb-excitation cross sections. The results support the scenario of a shape transition at 𝑁=60, giving rise to the coexistence of a highly deformed prolate and a spherical configuration in
98
Sr
, and are compared to predictions from several theoretical calculations. The experimental data suggest a significant contribution of the triaxal degree of freedom in the ground state of both isotopes. In addition, experimental information on low-lying states in
98
Rb
has been obtained.