Lifetime measurements in 129,131Xe

Abstract

Lifetimes of positive-parity levels in 129,131Xe have been measured by a new technique based on the recoil-distance method. The reduced E2 and M1 transition probabilities B(E2) and B(M1) deduced from these data have been compared with the predictions of nuclear models, in particular the interacting boson-fermion model (IBFM). Some dynamical symmetries of the latter are shown to display limited successes for the B(E2)'s but complete failures for the B(M1)'s, whereas calculations based on the full IBFM hamiltonian are in reasonable agreement with experiment for the two kinds of experimental data.