  A new approach to high energy evolution based on a linear equation for QCD
generating functional is developed. This approach opens a possibility for
systematic study of correlations inside targets, and, in particular, inside
realistic nuclei.
  Our results are presented as three new equations. The first one is a linear
equation for QCD generating functional (and for scattering amplitude) that sums
the 'fan' diagrams. For the amplitude this equation is equivalent to the
non-linear Balitsky-Kovchegov equation.
  The second equation is a generalization of the Balitsky-Kovchegov non-linear
equation to interactions with realistic nuclei. It includes a new correlation
parameter which incorporates, in a model dependent way, correlations inside the
nuclei.
  The third equation is a non - linear equation for QCD generating functional
(and for scattering amplitude) that in addition to the 'fan' diagrams sums the
Glauber-Mueller multiple rescatterings.
