  We have carried out a wide study of Cold Nuclear Matter (CNM) effects on
J/Psi production in d+Au, Cu+Cu and Au+Au collisions at sqrt(s_NN)=200 GeV. We
have studied the effects of three different gluon-shadowing parametrisations,
using the usual simplified kinematics for which the momentum of the gluon
recoiling against the J/Psi is neglected as well as an exact kinematics for a 2
-> 2 process, namely g+g -> J/psi+g as expected from LO pQCD. We have shown
that the rapidity distribution of the nuclear modification factor R_dAu, and
particularly its anti-shadowing peak, is systematically shifted toward larger
rapidities in the 2 -> 2 kinematics, irrespective of which shadowing
parametrisation is used. In turn, we have noted differences in the effective
final-state nuclear absorption necessary to fit the PHENIX d+Au data. Taking
advantage of our implementation of a 2 -> 2 kinematics, we have also computed
the transverse momentum dependence of the latter nuclear modification factor,
which cannot be predicted with the usual simplified kinematics. All the
corresponding observables have been computed for Cu+Cu and Au+Au collisions and
compared to the PHENIX and STAR data. Finally, we have extracted the effective
nuclear absorption from the recent measurements of R_CP in d+Au by the PHENIX
collaboration.
