The analytic continuation of the high–energy quark–quark scattering amplitude

It is known that the high–energy quark–quark scattering amplitude can be described by the expectation value of two lightlike Wilson lines, running along the classical trajectories of the two colliding particles. Generalizing the results of a previous paper, we give here the general proof that the expectation value of two infinite Wilson lines, forming a certain hyperbolic angle in Minkowski space–time, and the expectation value of two infinite Euclidean Wilson lines, forming a certain angle in Euclidean four–space, are connected by an analytic continuation in the angular variables. This result could be used to evaluate the high–energy scattering amplitude directly on the lattice.