Instantons and vacuum condensates in supersymmetric theories

Correlators (W2(x), S2(0)), where W is the superfield strength and S is the chiral matter field are considered in a supersymmetric theory with a single flavour. Because of the supersymmetry, the correlators are independent of coordinates and vanish in the perturbation theory. It is shown that even in the limit of vanishing x instanton of specific dimensios rho approximately 1/v, where v is the vacuum expectation value for the scalar field, contribute substantially, not only instantons of dimensions rho approximately x, as has been known previously. Theories are discussed where v >> Λ (Λ is a parameter which determines the effective coupling constant). In this case both types of contributions can be taken into account consistently. In is show, in particular, that the resulting correlator is related to the contribution from instantons of zero dimension, when expressed in terms of a new variable which is naturally called a supersymmetrical extension of the instanton dimension. The factorization of the correlators and their independence of space coordinates are quite evident in this representation