The T=2 mirrors 36Ca and 36S: A test for isospin symmetry of shell gaps at the driplines

Autor: F. C. L. Crespi, Zs. Podolyák, S. Chmel, T. Beck, L. Caceres, A. Banu, Helmut Weick, S.K. Mandal, J. Grȩbosz, F. Becker, F. Camera, J. Gerl, Norio Saito, P. Reiter, P. Bednarczyk, Benedicte Million, H. Schaffner, H. Grawe, N. Kurz, H. J. Wollersheim, H. Hübel, T. Striepling, A. Maj, Yutaka Utsuno, O. Kavatsyuk, I. Kojouharov, M. Kmiecik, M. Seidlitz, A. Richard, J. Walker, A. Al-Khatib, M. Górska, W. Meczynski, O. Wieland, T. Saito, P. Doornenbal, M. Kavatsyuk, R. Lozeva, Hans Geissel, A. Bracco, G. Benzoni, A. Bürger, Takaharu Otsuka, M. Winkler, N. Warr
Rok vydání: 2007
Předmět:
Zdroj: Physics Letters B. 647:237-242
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2007.02.001
Popis: The first excited 2+2+ state of 36Ca has been identified by its γ -decay, exploiting the two-step fragmentation technique at the FRS-RISING setup at GSI. This is the heaviest Tz=−2Tz=−2 nucleus in the Segré chart in which a γ-decay of an excited state has been observed. A stable beam of 40Ca at View the MathML source420AMeV impinged on a primary 9Be target. Out of the secondary beam of fragmentation products, 37Ca was separated by the FRS and struck on a second 9Be target at the final focus of the FRS. The energy for the View the MathML source21+ decay of 36Ca was determined to be 3015(16) keV, which is 276 keV lower than in its T=2T=2 mirror 36S. This mirror energy difference (MED) is discussed in the framework of shell model calculations using a 16O core, the sd shell isospin symmetric interaction USD and experimental single-particle energies from 17O and 17F. The results show that the MED within the sd shell provide a sensitive test for the evolution of the N , Z=14,16Z=14,16 subshell gaps towards the driplines. Especially the N , Z=16Z=16 gap is determined by Thomas–Ehrman shift in the A=17A=17, T=1/2T=1/2 isospin doublet, while Coulomb effects are found to have marginal influence. ispartof: Physics Letters B vol:647 issue:4 pages:237-242 status: published
Databáze: OpenAIRE
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