  We have carried out a wide study of shadowing and antishadowing effects on
\jpsi\ production in \dAu\ collisions at $\sqrt{s_{NN}}=200$ GeV. We have
studied the effects of three different gluon nPDF sets, using the exact
kinematics for a $2\to 2$ process, namely $g+g\to J/\psi+g$ as expected from LO
pQCD. We have computed the rapidity dependence of \RCP\ and $R_{d\rm Au}$ for
the different centrality classes of the PHENIX data. For mid rapidities, we
have also computed the transverse-momentum dependence of the nuclear
modification factor, which cannot be predicted with the usual $2\to 1$
simplified kinematics. All these observables have been compared to the PHENIX
data in \dAu\ collisions.
