Abstract
The reactions ppYKN are studied under the hypothesis of a dominant contribution from the exchange of a pseudoscalar meson (π or K) between the initial protons. The difficulty of a rigorous theoretical treatment of a true three-body final state is circumvented by assuming that the various damping effects at large momentum transfers (form factors, absorption) can be described in terms of a simple multiplicative cutoff function. Also, the assumptions and approximations which usually come into play in the theoretical analysis of these reactions are discussed critically. It is found that the agreement between theory and experiment is fairly good, within the limits of the model.