Shape coexistence and the N=28 shell closure far from stability

Citation
F. Sarazin et al., Shape coexistence and the N=28 shell closure far from stability, HYPER INTER, 132(1-4), 2001, pp. 147-152
Citations number
21
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
HYPERFINE INTERACTIONS
ISSN journal
0304-3843 → ACNP
Volume
132
Issue
1-4
Year of publication
2001
Pages
147 - 152
Database
ISI
SICI code
0304-3843(2001)132:1-4<147:SCATNS>2.0.ZU;2-7
Abstract
A mass measurement experiment by a time of flight method with the SPEG spec trometer at GANIL has been performed to investigate the N=20 and N=28 shell closures far from stability. The masses of 31 neutron-rich nuclei in the r ange A=29-47 have been measured. The precision of 19 masses has been signif icantly improved and 12 masses were measured for the first time. The neutro n-rich Cl, S and P isotopes are seen to exhibit a change in shell structure around N=28. Comparison with shell model and relativistic mean field calcu lations demonstrate that the observed effects arise from deformed prolate g round state configurations associated with shape coexistence. The evidence of an isomeric state in the S-43 and its interpretation by a shell model ca lculation confirm the analysis of the masses and constitutes the first evid ence: of the predicted shape coexistence around N=28.