Nuclear structures of 126Cs, 124La

Study of nuclear structure of doubly odd nuclei in the mass region A ≅ 130 is in progress by the NORDBALL collaboration. Gamma-gamma coincidence measurements have been done by the NORDBALL array consisting of 20 Compton suppressed Ge detectors. For detection of low energy γ-rays and X-rays, a LEP counter of 13 mm thick was employed as one of the Ge detectors. Excited states of 126Cs were created by the reaction 116Cd(14N,4n)126Cs at 65 MeV bombarding energy. Level structure of 124La was investigated by the reaction of 92Mo(35Cl,2pn)124La at 150 MeV bombarding energy. For those three data set, in total about 1.5 x 109 events of γ-γ coincidence data were recorded. At the present analysis of the data, four band structures were found in 126Cs. The signature inversion in the yrast bands has been clearly observed. It is consistent with the systematics of cesium isotopes. In the data set of the 35Cl + 92Mo reaction, several band structures have been newly observed. The three of the bands were assigned to 124La by the additional experiments of excitation function and neutron-gamma coincidence at University of Tsukuba. (author)