Lifetimes Measurements For Nd-134 And Neighboring Nuclei With The Coincidence-Plunger Technique

The Lifetimes of 12 excited states in Nd-134 were measured with a high precision by means of the GASP spectrometer applying the coincidence recoil-distance Doppler-shift method. The Pd-110(Si-28,xnyp) reaction was used at a beam energy of 125 MeV. The data were analyzed with the differential decay curve method and the derived lifetimes were used for a sensitive test of various nuclear models. The transition quadrupole moments (Q(t)) in the ground state band agree nicely with the predictions of both the rotor model and the O(6) symmetry of the interacting boson approximation up to the 4(g)(+) state of Nd-134. The Q(t) values for the 8(g)(+), 10(S1)(+), and 12(S1)(+) states, however, give evidence for a strong change of the nuclear deformation. The lifetimes of 12 low lying yrast states in the Ce-130,Ce-131,Ce-132, Pr-133,Pr-134, and Nd-135 nuclei have been also determined. [S0556-2813(99)01908-1].