학술논문
Studying Gamow-Teller transitions and the assignment of isomeric and ground states at $N=50$
Document Type
Working Paper
Author
Mollaebrahimi, Ali; Hornung, Christine; Dickel, Timo; Amanbayev, Daler; Kripko-Koncz, Gabriella; Plaß, Wolfgang R.; Andrés, Samuel Ayet San; Beck, Sönke; Blazhev, Andrey; Bergmann, Julian; Geissel, Hans; Górska, Magdalena; Grawe, Hubert; Greiner, Florian; Haettner, Emma; Kalantar-Nayestanaki, Nasser; Miskun, Ivan; Nowacki, Frédéric; Scheidenberger, Christoph; Bagchi, Soumya; Balabanski, Dimiter L.; Brencic, Ziga; Charviakova, Olga; Constantin, Paul; Dehghan, Masoumeh; Ebert, Jens; Gröf, Lizzy; Hall, Oscar; Harakeh, Muhsin N.; Kaur, Satbir; Kankainen, Anu; Knöbel, Ronja; Kostyleva, Daria A.; Kurkova, Natalia; Kuzminchuk, Natalia; Mardor, Israel; Nichita, Dragos; Otto, Jan-Hendrik; Patyk, Zygmunt; Pietri, Stephane; Purushothaman, Sivaji; Reiter, Moritz Pascal; Rink, Ann-Kathrin; Roesch, Heidi; Spătaru, Anamaria; Stanic, Goran; State, Alexandru; Tanaka, Yoshiki K.; Vencelj, Matjaz; Weick, Helmut; Winfield, John S.; Yavor, Michael I.; Zhao, Jianwei
Source
Subject
Language
Abstract
Direct mass measurements of neutron-deficient nuclides around the $N=50$ shell closure below $^{100}$Sn were performed at the FRS Ion Catcher (FRS-IC) at GSI, Germany. The nuclei were produced by projectile fragmentation of $^{124}$Xe, separated in the fragment separator FRS and delivered to the FRS-IC. The masses of 14 ground states and two isomers were measured with relative mass uncertainties down to $1\times 10^{-7}$ using the multiple-reflection time-of-flight mass spectrometer of the FRS-IC, including the first direct mass measurements of $^{98}$Cd and $^{97}$Rh. A new $Q_\mathrm{EC} = 5437\pm67$ keV was obtained for $^{98}$Cd, resulting in a summed Gamow-Teller (GT) strength for the five observed transitions ($0^+\longrightarrow1^+$) as $B(\text{GT})=2.94^{+0.32}_{-0.28}$. Investigation of this result in state-of-the-art shell model approaches sheds light into a better understanding of the GT transitions in even-even isotones at $N=50$. The excitation energy of the long-lived isomeric state in $^{94}$Rh was determined for the first time to be $293\pm 21$ keV. This, together with the shell model calculations, allows the level ordering in $^{94}$Rh to be understood.