Lifetime measurement for the 15/ 21- and 13/ 21- levels in Sn 129

Lifetimes of the 15/21- and 13/21- levels in Sn129 have been measured using γ-γ fast timing technique which come out to be 10(3) ps and 6(4) ps, respectively. The excited states were populated through internal transition decay of higher lying μs isomers in Sn129 produced as fission fragments and mass separated by the Lohengrin separator at Institut Laue-Langevin. The generalized centroid difference method was applied with four LaBr3(Ce) detectors, placed at the focal plane of the separator. The measured lifetimes and absolute transition probabilities are discussed in the light of large scale shell model calculations to interpret the single particle configurations and their mixing.