Disentangling the Regge Cut and Regge Pole in Perturbative QCD.

The high-energy limit of gauge-theory amplitudes features both a Regge pole and Regge cuts. We show how to disentangle these, and hence how to determine the Regge trajectory beyond two loops. While the nonplanar part of multiple Reggeon t-channel exchange forms a Regge cut, the planar part contributes to the pole along with the single Reggeon.