Interplay between particle and core ecitations in $^{133}$Sb

International audience; The decay of the one-proton valence nucleus 133Sb is studied usingthe cold-neutron induced fission of 235U and 241Pu targets. The experimentis performed at the ILL reactor in Grenoble, using a highly efficient HPGearray, also coupled to fast LaBr3(Ce) scintillators. High-spin excited statesabove the 16.6 s isomer are observed, and the lifetime of the 13/2+ and15/2+ states is measured by fast-timing techniques, revealing a complexnature of the wave functions. The experimental results are well-interpretedby a newly developed microscopic model which takes into account the couplingbetween the valence proton and excitations (both collective and noncollective)of the doubly magic 132Sn core.