Search for particle–vibration coupling in 65Cu

The lifetime of the 9/2 + state of 65 Cu, at 2534 keV, has been measured by fast timing techniques, in order to establish wether such state arises from a weak coupling between a p3=2 proton and the 3 octupole vibration at 3.56 MeV in the 64 Ni core. The 65 Cu nucleus was populated by the reaction 7 Li + 64 Ni at 32 MeV, at the Horia Hu- lubei National Institute of Physics and Nuclear Engineering (NIPNE) in Bucharest, and its -decay was detected by the ROSPHERE array. The measured lifetime coresponds to a B(E3) reduced transition probability to the ground state equal to 8.89 W.u., in agreement with theoretical predictions in the weak coupling limit.