Lifetime measurements of excited states in neutron-richAr44,46populated via a multinucleon transfer reaction

Lifetimes of low-lying excited states of the neutron-rich $^{44,46}\mathrm{Ar}$ nuclei, populated via multinucleon transfer reactions, are measured by means of the differential recoil distance Doppler shift method. The extracted electromagnetic transition probabilities are compared with previous intermediate-energy Coulomb-excitation measurements and with large-scale shell-model calculations. The increase in the deduced $B$($E2;{2}^{+}\ensuremath{\rightarrow}{0}^{+}$) transition probability from $^{44}\mathrm{Ar}$ to the closed-shell nucleus $^{46}\mathrm{Ar}$ contradicts the earlier results of Coulomb-excitation experiments. Shell-model calculations using different effective interactions agree with the new measured values.