SCHWARZSCHILD-LIKE CORRECTIONS TO GRAVITY FROM SUPERSTRINGS AT ONE LOOP

We examine the scattering between a scalar massive particle and a graviton at one loop in a four-dimensional type-II superstring model. The absence of a non-renormalization theorem for this case allows a one-particle reducible contribution to the amplitude containing a non-vanishing one-loop three-point function. Using the hyperelliptic language we compute its asymptotic behavior for s → ∞ and t → 0. We find a contribution to the amplitude which can be interpreted as a long-range correction to Newton's potential like the first-order expansion of the Schwarzschild metric. We compare also our results with ordinary one-loop Feynman diagrams. © 1990.