0(gs)+ -->2(1)+ transition strengths in 106Sn and 108Sn.
The reduced transition probabilities, B(E2; 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 gamma rays were detected by the highly segmented MINIBALL Ge-detector array. The results, B(E2;0(gs)+ -->2(1)+)=0.222(19)e2b2 for 108Sn and B(E2; 0(gs)+-->2(1)+)=0.195(39)e2b2 for 106Sn were determined relative to a stable 58Ni target. The resulting B(E2) values are approximately 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.
Ekström
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A
Physics Department, University of Lund, Box 118, SE-221 00 Lund, Sweden.
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Ames
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Butler
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Davinson
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BA
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Van Duppen
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Warr
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Weisshaar
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Zielińska
M
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