Lifetime measurements to investigate γ softness and shape coexistence in Mo102

Abstract

Lifetimes of low-spin excited states in Mo102 populated in a Mo100(O18,O16)Mo102 two-neutron transfer reaction were measured using the recoil-distance Doppler-shift technique at the Cologne FN Tandem accelerator. Lifetimes of the 21+, 41+, 61+, 02+, 2γ+, 3γ+ states and one upper limit for the lifetime of the 4γ+ state were obtained. The energy levels and deduced electromagnetic transition probabilities are compared with those obtained within the mapped interacting boson model framework with microscopic input from Gogny mean-field calculations. With the newly obtained signatures a more detailed insight in the γ softness and shape coexistence in Mo102 is possible and discussed in the context of the Z≈40 and N≈60 region. The nucleus of Mo102 follows the γ soft trend of the Mo isotopes. The properties of the 02+ state indicate, in contrast with the microscopic predictions, shape coexistence which also occurs in other N=60 isotones