Color dipoles and k_t factorization for nuclei
  We discuss applications of the color dipole approach to hard processes on nuclei. We focus on the relation to k_t--factorisation and the role of a nuclear unintegrated gluon distribution in single-- and two-- particle inclusive spectra in \gamma^*A and pA collisions. Linear k_t factorisation is broken for a wide class of observables, which we exemplify on the case of heavy quark p_t--spectra. 
N.N. Nikolaev, W. Sch\"afer, B.G. Zakharov, and V.R. Zoller