High-energy scattering in QCD and cross singularities of Wilson loops

We consider elastic quark-quark scattering at high energy and fixed transferred momentum. Performing factorization of soft-gluon exchanges into the Wilson-line expectation value we find that there is one-to-one correspondence between high-energy asymptotics in QCD and renormalization properties of the so-called cross singularities of the Wilson lines. Using this relation we show that the asymptotic behavior of the quark-quark scattering amplitude is controlled by a 2x2 matrix of the cross anomalous dimensions. We evaluate the matrix of the cross anomalous dimension to two-loop order and study the properties of the obtained expressions to higher loop order. ((orig.))