Ultrahigh-Resolution -Ray Spectroscopy of 156 Gd: ATest of Tetrahedral Symmetry

M. Jentschel, W. Urban, J. Krempel, D. Tonev, J. Dudek, D. Curien, B. Lauss, G. de Angelis, and P. Petkov Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, F-38042 Grenoble, France Faculty of Physics, University of Warsaw, ul. Hoza 69, PL-00-681 Warsaw, Poland Institute for Nuclear Research and Nuclear Energy, BAS, BG-1784 Sofia, Bulgaria Departement de Recherches Subatomiques, Institut Pluridisciplinaire Hubert Curien, DRS-IPHC, 23 rue du Loess, BP 28, F-67037 Strasbourg, France Paul Scherrer Institut, CH-5232 Villigen-PSI, Switzerland Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy (Received 26 February 2010; published 4 June 2010)