Evidence for coexisting shapes through lifetime measurements in 98Zr

• Published in: Physical review letters 2018
• Main Authors: Singh, Purnima, Korten, Wolfram, Hagen, Trine Wiborg, Görgen, Andreas, Grente, Lucie, Salsac, Marie Delphine, Farget, F, Braunroth, T, Bruyneel, Bart, Celikovic, I, Clement, E, de France, G, Delaune, O, Dewald, Alfred, Dijon, Aurore, Delaroche, Jean Paul, Girod, Michel, Hackstein, Matthias, Jacquot, Bertrand, Libert, J, Litzinger, J, Ljungvall, Joa, Louchart, C, Gottardo, Andrea, Michelagnoli, Caterina, Napoli, D.R, Otsuka, Takaharu, Pillet, N, Recchia, Francesco, Rother, Wolfram, Sahin, Eda, Siem, Sunniva, Sulignano, B, Togashi, T, Theisen, Christophe, Valiente-Dobón, Jose Javier
• Format: Article
• Language: Norwegian
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.121.192501

The lifetimes of the first excited 2þ, 4þ, and 6þ states in 98Zr were measured with the recoil-distance Doppler shift method in an experiment performed at GANIL. Excited states in 98Zr were populated using the fission reaction between a 6.2 MeV=u 238U beam and a 9 Be target. The γ rays were detected with the EXOGAM array in correlation with the fission fragments identified by mass and atomic number in the VAMOS++ spectrometer. Our result shows a very small BðE2; 2þ 1 → 0þ 1 Þ value in 98Zr, thereby confirming the very sudden onset of collectivity at N ¼ 60. The experimental results are compared to large-scale Monte Carlo shell model and beyond-mean-field calculations. The present results indicate the coexistence of two additional deformed shapes in this nucleus along with the spherical ground state.