UNITARITY CORRECTIONS AND HIGH-FIELD STRENGTHS IN HIGH-ENERGY HARD COLLISIONS

Unitarity corrections to the BFKL description of high energy hard scat tering are viewed in large N-c QCD in light-cone quantization. In a ce nter of mass frame unitarity corrections to high energy hard scatterin g are manifestly perturbatively calculable and unrelated to questions of parton saturation. In a frame where one of the hadrons is initially at rest unitarity corrections are related to parton saturation effect s and involve potential strengths A(mu) similar to 1/g. In such a fram e we describe the high energy scattering in terms of the expectation v alue of a Wilson loop. The large potentials A(mu) similar to 1/g are s hown to be pure gauge terms allowing perturbation theory to again desc ribe unitarity corrections and parton saturation effects. Genuine nonp erturbative effects only come in at energies well beyond those energie s where unitarity constraints first become important. (C) 1997 Elsevie r Science B.V.