Nonlinear k⊥-factorization for forward dijets in deep inelastic scattering off nuclei in the saturation regime

We develop a QCD description of the breakup of photons into forward dijets in small-x deep inelastic scattering off nuclei in the saturation regime. Based on the color dipole approach, we derive a multiple scattering expansion for intranuclear distortions of the jet-jet transverse momentum spectrum. Special attention is paid to the non-Abelian aspects of the propagation of color dipoles in the nuclear medium. We report a nonlinear k⊥-factorization formula for the breakup of photons into dijets in terms of the collective Weizsäcker-Williams glue of nuclei defined in [5, 6]. For hard dijets with the transverse momenta above the saturation scale, the azimuthal decorrelation (acoplanarity) momentum is on the order of the nuclear saturation momentum QA. For minijets with the transverse momentum below the saturation scale, the nonlinear k⊥-factorization predicts a complete disappearance of the jet-jet correlation. We comment on possible relevance of the nuclear decorrelation of jets to the experimental data from the STAR-RHIC Collaboration.