Interplay between Single-Particle and Collective Effects in the Odd-A Cu Isotopes beyond N = 40

Collective properties of the low-lying levels in the odd-𝐴
67–73
Cu
were investigated by Coulomb excitation with radioactive beams. The beams were produced at ISOLDE and postaccelerated by REX-ISOLDE up to 2.99 MeV/u. In
67,69
Cu
, low-lying 1/2−, 5/2−, and 7/2− states were populated. In
71,73
Cu
, besides the known transitions deexciting the single-particle-like 5/2− and core-coupled 7/2− levels, 𝛾 rays of 454 and 135 keV, respectively, were observed for the first time. Based on a reanalysis of 𝛽-decay work and comparison with the systematics, a spin 1/2− is suggested for these excited states. Three 𝐵⁡(𝐸⁢2) values were determined in each of the four isotopes. The results indicate a significant change in the structure of the odd-𝐴 Cu isotopes beyond 𝑁 =40 where single-particle-like and collective levels are suggested to coexist at very low excitation energies.

Authors: I. Stefanescu, G. Georgiev, D.L. Balabanski, N. Blasi, A. Blazhev, N. Bree, J. Cederkäll, T.E. Cocolios, T. Davinson, J. Diriken, J. Eberth, A. Ekstöm, D. Fedorov, V.N. Fedosseev, L.M. Fraile, S. Franchoo, K. Gladnishki, M. Huyse, O. Ivanov, V. Ivanov, J. Iwanicki, J. Jolie, T. Konstantinopoulos, Th. Kröll, R. Krücken, U. Köster, A. Lagoyannis, G. Lo Bianco, P. Maierbeck, B.A. Marsh, P. Napiorkowski, N. Patronis, D. Pauwels, G. Rainovski, P. Reiter, K. Riisager, M. Seliverstov, G. Sletten, J. Van de Walle, P. Van Duppen, D. Voulot, N. Warr, F. Wenander, K. Wrzosek

Doi: 10.1103/PhysRevLett.100.112502

Issue number:

Journal: Phys. Rev. Lett.

Page number: 112502

Published on: 2008-03-21

Year: