Violation of a simple factorized form of QCD amplitudes and Regge cuts

A simple factorized form of high energy QCD amplitudes with gluon quantum numbers in the cross channels and negative signature is known to be violated in the next-to-next-to-leading logarithmic approximation (NNLLA). The violation is explained by contributions of three-Reggeon cuts. The contributions of the cuts to the elastic amplitudes and the consequent need to change the scheme of derivation of the BFKL equation in the NNLLA is discussed.