First direct lifetime measurement of the 21+state in72,74Zn: New evidence for a shape transition betweenN=40andN=42close toZ=28
| Autor: | W. Rother, D. Pantelica, F. Ibrahim, S. Grévy, S. Myalski, L. Perrot, Georgi P. Georgiev, M. Hackstein, C. Fransen, G. de Angelis, G. Burgunder, M. Kmiecik, L. Coquard, I. Stefan, Emyr Clement, I. Matea, Zs. Dombrádi, C. Borcea, A. Buta, A. Dijon, F. de Oliveira Santos, S. Franchoo, Mohsen Harakeh, Predrag Ujić, J. A. Scarpaci, F. Negoita, L. Gaudefroy, P. Bednarczyk, F. Rotaru, B. Mouginot, L. Caceres, A. Dewald, A. Bürger, M. Assié, A. Maj, Th. Pissulla, J. C. Thomas, C. Mihai, C. Stodel, M. Niikura, E. Fiori, G. Friessner, O. Möller, F. Azaiez, O. Kamalou, D. Verney, R. Lozeva |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | Physical Review C. 85 |
| ISSN: | 1089-490X 0556-2813 |
| Popis: | We report here the first direct lifetime measurement of the 2(1)(+) state in Zn-72,Zn-74. The neutron-rich beam was produced by in-flight fragmentation of Ge-76 at the Grand Accelerateur National d'Ions Lourds and separated with the LISE spectrometer. The 2(1)(+) state was excited by inelastic scattering and knock-out reaction on a CD2 target and its lifetime was measured by the recoil-distance Doppler-shift method with the Koln plunger device combined with the EXOGAM detectors. The lifetimes of the 2(1)(+) states in Zn-72,Zn-74 were determined to be 17.9(18) and 27.0(24) ps, which correspond to reduced transition probabilities B(E2; 2(1)(+)-> 0(+)) = 385(39) and 370(33) e(2) fm(4), respectively. These values support the idea of a systematic maximum of collectivity at N = 42 for Zn, Ge, and Se nuclei. In addition, the available systematics in the neighboring nuclei point toward a transition from a spherical oscillator at N = 40 to complete gamma-softness at N = 42. |
| Databáze: | OpenAIRE |
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