NONOBSERVATION OF C-12 CLUSTER DECAY OF BA-114

By means of the on-line mass separator at Gesellschaft fur Schwerionen forschung, Darmstadt, we produced Ba-114 through the Ni-51(Ni-58,2n) r eaction, separated it as a (BaF+)-Ba-114-F-19 beam, and implanted it i nto a stopper foil positioned in the center of an array of track detec tors, which were used to search for C-12 radioactivity of Ba-114. A to tal number of (5.4+/-1.7)X10(4 114)Ba atoms were implanted. No C-12 ev ent was found after a total exposure time of 116 h, corresponding to a Ni-58 beam dose of 1.3X10(17). The resulting upper limit of 3.4x10(-5 ) (84% C.L.) for the branching ratio for C-12 decay of Ba-114 is consi derably lower than the limits obtained in previous experiments, which represents an inconsistency at levels of more than 90%. A semiempirica l estimate of 19.3 MeV for the upper limit of the Q value for C-12 dec ay of Ba-114 is derived.