Perturbation theory in the Federbush model: induced interaction terms

Elastic scattering and production amplitudes are studied in a theory of two massive spinor fields in two space-time dimensions with a current-pseudocurrent interaction (the Federbush model). In contrast to a claim in the recent literature, the results of perturbation theory in the lowest non-trivial orders are consistent with the explicit solution, although massive-Thirring-coupling counter terms must be introduced in order to reproduce the vanishing particle-antiparticle amplitudes of the exact solution. (Auth.)