MASS CORRECTIONS TO SOME INSTANTON EFFECTS

We develop an approximation scheme which allows us to determine the massive scalar propagator in a background instanton field to second order in a supposedly small mass parameter m, i.e., including terms of order m2ln m and m2, and the massive spinor propagator to the same order. The approximate scalar propagator is used to study the mass corrections to the short-distance behaviour of a two-point scalar loop. Applying this as a toy model for σ(e+e- → anything) we find that the large momentum behaviour of the leading mass corrections is at most of the same order as the massless instanton effects. © 1979.