Low-energy Coulomb excitation of $^{96,98}$Sr beams

E. Clément (1) , M. Zielinska (2) , S. Péru (3) , H. Goutte (2) , S. Hilaire (3) , A. Görgen , W. Korten (2) , D. Doherty (2) , B. Bastin (1) , C. Bauer , A. Blazhev , N. Bree , B. Bruyneel , A. Butler , J. Butterworth , J. Cederkäll , P. Delahaye (1) , A. Dijon (1) , A. Ekström , C. Fitzpatrick , C. Fransen , G. Georgiev (4) , R. Gernhäuser , H. Hess , J. Iwanicki , D. Jenkins , A. Larsen , J. Ljungvall (4) , R. Lutter , P. Marley , K. Moschner , J. Napiorkowski , J. Pakarinen , A. Petts , P. Reiter , T. Renstrøm , M. Seidlitz , B. Siebeck , S. Siem , C. Sotty , J. Srebrny , I. Stefanescu , M. Tveten , J. van de Walle , M. Vermeulen , D. Voulot , N. Warr , F. Wenander , A. Wiens , H. de Witte , K. Wrzosek-Lipska

1 GANIL - Grand Accélérateur National d'Ions Lourds
2 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
3 DAM - Direction des Applications Militaires
4 CSNSM - Centre de Sciences Nucléaires et de Sciences de la Matière

The structure of neutron-rich 96,98Sr 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 98Sr, 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 98Rb has been obtained.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

E. Clément, M. Zielinska, S. Péru, H. Goutte, S. Hilaire, et al.. Low-energy Coulomb excitation of $^{96,98}$Sr beams. Physical Review C, 2016, 94 (5), pp.054326. ⟨10.1103/PhysRevC.94.054326⟩. ⟨in2p3-01404614⟩