  Production of heavy photons (Drell-Yan), gauge bosons, Higgs bosons, heavy
flavors, which is treated within the QCD parton model as a result of hard
parton-parton collision, can be considered as a bremsstrahlung process in the
target rest frame. In this review, we discuss the basic features of the
diffractive channels of these processes in the framework of color dipole
approach. The main observation is a dramatic breakdown of diffractive QCD
factorisation due to the interplay between soft and hard interactions, which
dominates these processes. This observation is crucial for phenomenological
studies of diffractive reactions in high-energy hadronic collisions.
