Color dipole BFKL-Regge factorization and high-energy photon-photon scattering

Based on the color dipole representation, we investigate consequences for t he gamma*gamma*, gamma*gamma scattering of the finding by Fadin, Kuraev, an d Lipatov that the incorporation of asymptotic freedom into the BFKL equati on makes the QCD pomeron a series of isolated poles in the angular momentum plane. The emerging color dipole BFKL-Regge factorization allows us to rel ate in a model-independent way the contributions of each BFKL pole to the g amma*gamma*, gamma*gamma scattering and the deep inelastic scattering on pr otons. Numerical predictions based on our early work on the color dipole BF KL phenomenology of the deep inelastic scattering on protons gives a good a greement with the recent experimental data from OPAL and L3 experiments at LEP200. We discuss the role of nonperturbative dynamics and predict a prono unced effect of the Regge-factorization breaking due to large unfactorizabl e nonperturbative corrections to the perturbative vacuum exchange. We comme nt on the salient features of the BFKL-Regge expansion for the gamma*gamma* , gamma*gamma scattering including the issue of the decoupling of subleadin g BFKL poles and the soft plus rightmost hard BFKL pole dominance. (C) 2001 MAIK "Nauka/Interperiodica".