  We consider the J/Psi production in proton (deuteron) -- nucleus collisions
at high energies. We argue that the production mechanism in this case is
different from that in pp collisions due to gluon saturation in the nucleus and
formation of the Color Glass Condensate. At forward rapidities (in the proton
fragmentation region), the production of J/Psi is increasingly suppressed both
as a function of rapidity and centrality. On the other hand, at backward
rapidities at RHIC (in the fragmentation region of the nucleus) the coherent
effects lead to a modest enhancement of the production cross section, with the
nuclear modification factor R(J/Psi) increasing with centrality. We find that
the J/Psi production cross section exhibits at forward rapidities the limiting
fragmentation scaling established previously for soft processes; in the energy
range studied experimentally, it manifests itself as an approximate "xF
scaling".
