Causal perturbation theory approach to Yukawa’s model

Neutral Yukawa’s model for the description of the interaction between nucleons and pions is studied in the framework of causal perturbation theory, an axiomatic S-matrix quantum field theory in which ultra-violet divergences do not arise as a consequence of a careful splitting of the causal distribution into its retarded and advanced parts. We calculate the scattering cross sections and radiative corrections, including the vertex function for this model, and show that all the normalization constants of these terms can be fixed by requirements on the physical values of the masses and coupling constant. We end with an analysis on the normalizability of this model and the possible self-interaction terms which can arise in higher-order calculations.