Regge Poles in QCD

Basic properties of Regge poles are reviewed. Regge poles are considered from both t-channel and s-channel points of view. The main part of the review is devoted to the Regge poles in QCD. The method of the Wilson-loop path integral is used to calculate trajectories of Regge poles for $q-\bar q$ and gluonic states. The problem of the Pomeron in QCD is discussed in details. It is shown how to use the 1/N-expansion for classification of reggeon diagrams in QCD. The role of Regge cuts in reggeon theory is discussed and their importance for high-energy phenomenology is emphasized. Models based on the reggeon calculus, 1/N-expansion in QCD and string picture of interactions at large distances are reviewed and are applied to a broad class of phenomena in strong interactions. It is shown how to apply the reggeon approach to small-x physics in deep inelastic scattering.