| A. Gorgen, E. Cl'ement, A. Chatillon, A. Dewald, W. Korten, Y. Le Coz, N. Marginean, B. Melon, R. Menegazzo, O. M"oller, Ch. Theisen, D. Tonev, C.A. Ur, K.O. Zell |
Lifetimes of excited states in the ground-state bands of $^{74}$Kr and $^{76}$Kr were measured using the recoil-distance Doppler shift and the differential decay curve methods. The states were populated in the $^{40}$Ca($^{40}$Ca,${\\alpha}2p$) and $^{40}$Ca($^{40}$Ca,$4p$) reactions. Gamma rays were detected with the GASP array which was
coupled to the Cologne Plunger device. The results resolve discrepancies between earlier lifetime measurements and a recent Coulomb excitation experiment. Experimental transition rates are
compared to theoretical calculations. The results support a strong mixing between prolate and oblate configurations for the low-spin states, and represent an important basis for the interpretation and understanding of the shape coexistence phenomenon in this mass region. |
