PERTURBATION EXPANSION OF MACROMOLECULES WITH REALISTIC PAIR INTERACTIONS IN 3 AND 4 DIMENSIONS

We calculated the first-order perturbation expansion of the mean-squar e end-to-end distance of polymers in three and four space dimensions. The segments of the chain were assumed to interact via a pair potentia l with a short-range repulsive and an additional attractive part. For a purely repulsive potential, the well-known results of the delta-func tion-pseudopotential approach are recovered, whereas the inclusion of an attractive part leads to a non-vanishing contribution even for a va nishing binary cluster integral.