Isomer studies in the vicinity of the doubly-magic nucleus 100Sn: Observation of a new low-lying isomeric state in 97Ag
C. Hornung, Daler Amanbayev, I. Dedes, Gabriella Kripkó-Koncz, Ivan Miskun, Noritaka Shimizu, Samuel Ayet San Andrés, J. Bergmann, T. Dickel, J. Dudek, Jens Ebert, H. Geißel, M. Górska, Hubert Grawe, Florian Greiner, E. Haettner, Takaharu Otsuka, W. R. Plaß, S. Purushothaman, Ann-Kathrin Rink, C. Scheidenberger, H. Weick, S. Bagchi, A. Blazhev, Olga Charviakova, D. Curien, A. Finlay, Satbir Kaur, W. Lippert, Jan-Hendrik Otto, Z. Patyk, S. Piétri, Y. Tanaka, Y. Tsunoda, John S. Winfield
Abstract
Long-lived isomeric states in 97Ag and 101−109In were investigated with the FRS Ion Catcher at GSI. In the isotope 97Ag, a long-lived (1/2−) isomeric state was discovered, and its excitation energy was determined to be 618(38) keV. This is simultaneously the first discovery of a nuclear isomeric state by multiple-reflection time-of-flight mass spectrometry. The measured excitation energies were compared to large-scale shell-model calculations, which indicated the importance of core excitation around 100Sn. Furthermore, advanced mean-field calculations for the 97Ag nucleus and relevant neighboring nuclei were performed, which have contributed to a better understanding of the repetitive appearance of certain isomeric structures in neighboring nuclei, and which have supported the discovery of the isomeric state in 97Ag in a global shell-evolution scheme.