Interpretation of Λ-attachment probabilities in hyperonic fission

We calculate the correlation diagrams for Λ-hyperonic levels in 238U along several fission paths with different asymmetry. Several mechanisms 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 thermally excited nucleons and with thermal surface phonons. Only if the Λ-nucleon residual interaction is strong enough to establish thermal equilibrium before fission does the attachment probability as a function of the mass split allow us to determine a fission velocity between saddle and scission and temperature. However, for that purpose the statistics of measured data has to be improved considerably