Dynamic chirality in mass regions A=105 and A=130

Abstract

Chiral symmetry is dichotomic and its spontaneous breaking by the axial angular momentum vector leads to a pair of degenerate ΔI = 1 rotational bands, called chiral doublet bands. In many cases the energy degeneracy of the chiral candidate bands has almost been observed but the transition probabilities of the analogue states have been found to be different. In the angular momentum region where chirality sets in the B(E2) values of the electromagnetic transitions deexciting analogue states of the chiral twin bands should be almost equal. Correspondingly the B(M1) values should exhibit staggering. Experimental data for two nuclei from different mass regions are compared with theoretical predictions. Exited states in 134Pr were populated in the fusion-evaporation reaction 119Sn(19F, 4n)134Pr, while excited states in 102Rh were populated in the fusion-evaporation reaction 94Zr(11B, 3n)102Rh. Our lifetime measurements and level-scheme investigations show that there are similarities in both chiral candidates nuclei related to dynamic chirality.