Gauge invariant effective action for high energy processes in QCD Original Research Article

The Born amplitudes for quasi-multi-Regge kinematics of produced gluons are constructed in accordance with the Feynman rules including, apart from the usual Yang-Mills vertices, also an infinite number of induced vertices. The new vertices describe the interaction of physical gluons produced in direct channels with the reggeized gluons propagating in crossing channels. The non-linear gauge invariant effective action generating these Feynman rules is constructed with the use of the Wilson contour integrals. By integrating over the physical degrees of freedom the reggeon action is derived.