Inelastic diffractive-dissociation cross section in. pi. /sup -/p interactions at 200 GeV/c

For nondiffractive ..pi../sup -/p interactions at high energy we find that the dependence of the cross section on charge multiplicity in each c.m. hemisphere exhibits Koba-Nielsen-Olesen scaling. We use this behavior to extract a cross section for diffractive excitation of 3.4 +- 0.2 mb at 200 GeV/c. We attribute approx. 55% of this to pion excitation, with a mean breakup charge multiplicity of approx. 2.9, approx. 30% to proton excitation, with mean charge multiplicity approx. 2.2 and approx. 15% to double excitation. We believe this technique is widely applicable for extracting the diffractive component in hadronic interactions.