ABSORPTION AND RECOIL OF FUNDAMENTAL STRINGS BY D-STRINGS

The inclusive absorption cross section of a fundamental IIB string to a D-string is calculated perturbatively, The leading-order result agre es with the estimate based on the stringy Higgs mechanism via the Crem mer-Scherk coupling, It is argued that the subleading-order correction is dominated by purely planar diagrams in the large mass limit, The c orrection represents the conversion of the binding energy into the loc al recoil process of the fundamental string and the D-string bound sta te. We show their presence explicitly in the next leading order. (C) 1 997 Elsevier Science B.V.