Testing refined shell-model interactions in the sd shell: Coulomb excitation of 26Na

B. Siebeck,1 M. Seidlitz,1 A. Blazhev,1 P. Reiter,1,* R. Altenkirch,1 C. Bauer,2 P. A. Butler,3 H. De Witte,4 J. Elseviers,4 L. P. Gaffney,4 H. Hess,1 M. Huyse,4 T. Kroll,2,5 R. Lutter,6 J. Pakarinen,7,8 N. Pietralla,2 F. Radeck,1 M. Scheck,9,10 D. Schneiders,1 C. Sotty,4,11 P. Van Duppen,4 M. Vermeulen,12 D. Voulot,11 N. Warr,1 and F. Wenander11 (for the MINIBALL and REX-ISOLDE Collaborations) 1Institut fur Kernphysik, Universitat zu Koln, 50937 Koln, Germany 2Institut fur Kernphysik, Technische Universitat Darmstadt, 64289 Darmstadt, Germany 3Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom 4Instituut voor Kernen Strahlingsfysica, KU Leuven, 3001 Leuven, Belgium 5Physik Department E12, Technische Universitat Munchen, 85748 Garching, Germany 6Department of Physics, Ludwig Maximilian Universitat Munchen, 85748 Garching, Germany 7Department of Physics, University of Jyvaskyla, FI-40014 Jyvaskyla, Finland 8Helsinki Institute of Physics, P.O. Box 64, FI-00014 Helsinki, Finland 9School of Engineering, University of the West of Scotland, Paisley PA1 2BE, United Kingdom 10Scottish Universities Physics Alliance, Glasgow G12 8QQ, United Kingdom 11Physics Department, ISOLDE, CERN, 1211 Geneva 23, Switzerland 12Nuclear Physics Group, University of York, York YO10 5DD, United Kingdom (Received 28 October 2014; revised manuscript received 12 December 2014; published 15 January 2015)