Lifetime determination in Hg-190,Hg-192,Hg-194,Hg-196 via gamma-gamma fast-timing spectroscopy

Lifetimes of 2(1)(+) and 4(1)(+) states in Hg-190,Hg-192,Hg-194,Hg-196 and of some negative parity band members were measured using the gamma-gamma fast-timing technique with a high-purity germanium and LaBr3(Ce) detector array. The excited states were populated via fusion-evaporation reactions using the Tandem Van de Graaff accelerator of the Institute of Nuclear Physics in Cologne, Germany. The derived reduced transition probabilities of the 2(1)(+)-> 0(1)(+) and 4(1)(+) -> 2(l)(+) transitions are discussed in the framework of the interacting boson approximation with two models using configuration mixing: a phenomenological one and a microscopical one. Both models describe the observed quantities of the nuclei within the experimental uncertainties.