0+ gs →2+ 1 Transition Strengths in 106 Sn and 108 Sn

The reduced transition probabilities, 𝐵⁡(𝐸⁢2;0+
gs →2+
1), have been measured in the radioactive isotopes
108,106
Sn
using subbarrier Coulomb excitation at the REX-ISOLDE facility at CERN. Deexcitation 𝛾 rays were detected by the highly segmented MINIBALL Ge-detector array. The results, 𝐵⁡(𝐸⁢2;0+
gs →2+
1) =0.222⁢(19)⁢𝑒2⁢𝑏2 for
108
Sn
and 𝐵⁡(𝐸⁢2;0+
gs →2+
1) =0.195⁢(39)⁢𝑒2⁢𝑏2 for
106
Sn
were determined relative to a stable
58
Ni
target. The resulting 𝐵⁡(𝐸⁢2) values are ∼30% larger than shell-model predictions and deviate from the generalized seniority model. This experimental result may point towards a weakening of the 𝑁 =𝑍 =50 shell closure.

Authors: A. Ekstöm, J. Cederkäll, C. Fahlander, M. Hjorth-Jensen, F. Ames, P.A. Butler, T. Davinson, J. Eberth, F. Fincke, A. Görgen, M. Górska, D. Habs, A.M. Hurst, M. Huyse, O. Ivanov, J. Iwanicki, O. Kester, U. Köster, B.A. Marsh, J. Mierzejewski, P. Reiter, H. Scheit, D. Schwalm, S. Siem, G. Sletten, I. Stefanescu, G.M. Tveten, J. Van de Walle, P. Van Duppen, D. Voulot, N. Warr, D. Weißhaar, F. Wenander, M. Zielińska

Doi: 10.1103/PhysRevLett.101.012502

Issue number:

Journal: Phys. Rev. Lett.

Page number: 012502

Published on: 2008-07-02

Year: