INTERPRETATION OF LAMBDA-ATTACHMENT PROBABILITIES IN HYPERONIC FISSION

We calculate the correlation diagrams for LAMBDA-hyperonic levels in U -238 along several fission paths with different asymmetry. Several mec hanisms are discussed which control the occupation probability of the hyperonic states during fission: nonadiabatic effects, induced by the rate of change of the mean field, and collisions of the hyperon with t hermally excited nucleons and with thermal surface phonons. Only if th e A-nucleon residual interaction is strong enough to establish thermal equilibrium before fission does the attachment probability as a funct ion of the mass split allow us to determine a fission velocity between saddle and scission and temperature. However, for that purpose the st atistics of measured data has to be improved considerably.