  Nuclear suppression of charmonium production in proton-nucleus interactions
is poorly understood, what restrains our attempts to single out unusual effects
in heavy ion collisions. We develop a phenomenological approach, based on the
light-cone dynamics of charmonium production, which has much in common with
deep-inelastic scattering and Drell-Yan lepton pair production. The key
observation is the existence of a soft mechanism of heavy flavour production,
which scales in the quark mass and dominates shadowing corrections and
diffraction. It naturally explains the surprisingly strong nuclear suppression
of J/Psi at large Feynman-x_F. The low-x_F region is subject to a complicated
interplay of hard and soft mechanisms. With evaluated parameters we nicely
describe available data on charmonium production in proton-nucleus collisions.
Using these results we predict a new process, diffractive production of
charmonium on a nucleon target, which fraction in the total production rate of
charmonium is evaluated at 12%.
