Half-life and internal conversion electron measurements in low-lying levels of ^125,127Ba

The level properties in the low energy region of ^125,127Ba were studied through the decays of ^125,127La by using the JAERI on-line mass separator (JAERI-ISOL). The half-lives of the excited states and the internal conversion coefficients were determined for the first time by the β-γ delayed coincidence technique and by conversion electron measurements, respectively. The half-life of the long-lived isomeric state of ¹²⁷Ba (1.93 s) was determined by spectrum multiscaling measurements. Although the detailed decay schemes have been proposed, no evidence of a parity doublet has been observed. The level properties with respect to the transition probabilities are well interpreted by the Nilsson model.