Fate of k_perp-factorization for hard processes in nuclear environment
  Large thickness of heavy nuclei brings in a new scale into the pQCD description of hard processes in nuclear environment. The familiar linear $k_{\perp}$-factorization breaks down and must be replaced by a new concept of the nonlinear $k_{\perp}$-factorization introduced in \cite{Nonlinear}. I demonstrate the salient features of nonlinear $k_{\perp}$-factorization on an example of hard dijet production in DIS off heavy nuclei. I also discuss briefly the non-linear BFKL evolution for gluon density of nuclei. 
N.N. Nikolaev (Institut f. Kernphysik, Forschungszentrum J\"ulich,   Germany and L.D.Landau Institute for Theoretical Physic...