Question of dynamic chirality in nuclei: The case of Pr134

Lifetimes of exited states in Pr-134 were measured by means of the recoil distance Doppler-shift and Doppler-shift attenuation techniques. The branching ratios and the electric or magnetic character of the transitions were also investigated. The experiments were performed at IReS, Strasbourg, using the EUROBALL IV spectrometer, in conjunction with the inner bismuth germanate ball and the Cologne coincidence plunger apparatus. Exited states in Pr-134 were populated in the fusion-evaporation reaction Sn-119(F-19, 4n)Pr-134. The possible chiral interpretation of twin bands was investigated in the two-quasiparticle triaxial rotor and interacting boson-fermion-fermion models. The analysis of the wave functions has shown that the possibility for the angular momenta of the proton, neutron, and core to find themselves in the favorable, almost orthogonal geometry, is present but is far from being dominant. The structure is characterized by large beta and gamma fluctuations. The existence of doublets of bands in Pr-134 can be attributed to weak chirality dominated by shape fluctuations.