| J.Ljungvall, A.Gorgen, M.Girod, J.-P.Delaroche, A.Dewald, C.Dossat, W.Korten, B.Melon, R.Menegazzo, A.Obertelli, R.Orlandi, P.Petkov, T.Pissulla, S.Siem, R.P.Singh, J.Srebrny, Ch.Theisen, C.A.Ur, J.J.Valiente-Dobon, K.O.Zell, M.Zielinska |
Lifetimes of states in the ground-state bands of $^{70}$Se and $^{72}$Se were measured using the recoil-distance Doppler shift method following the reactions $^{40}$Ca($^{36}$Ar,${\\alpha}2p$)$^{70}$Se and
$^{40}$Ca($^{36}$Ar,$4p$)$^{72}$Se. The results deviate significantly from earlier measurements, requiring a revision of the conclusions drawn from a recent Coulomb excitation experiment concerning the shape of $^{70}$Se. Hartree-Fock-Bogolyubov-based configuration mixing
calculations using the Gogny D1S interaction have been performed and compared to the new experimental results. Both experiment and theory
find an oblate shape for the $2_1^+$ state in $^{70}$Se, resulting in a coherent description of the shape coexistence and shape evolution in the light Se isotopes. |
