Centrality, rapidity, and transverse-momentum dependence of cold nuclear matter effects on J/ψ production in dAu, CuCu, and AuAu collisions at √sNN=200 GeV

We have carried out a wide study of cold nuclear matter (CNM) effects on J/ψ production in dAu, CuCu and AuAu collisions at √sNN=200 GeV. We have studied the effects of three different gluon-shadowing parametrizations, using the usual simplified kinematics for which the momentum of the gluon recoiling against the J/ψ is neglected as well as an exact kinematics for a 2→2 process; namely g+g→J/ψ+g as expected from LO pQCD. We have shown that the rapidity distribution of the nuclear modification factor RdAu, and particularly its antishadowing peak, is systematically shifted toward larger rapidities in the 2→2 kinematics, irrespective of which shadowing parametrization is used. In turn, we have noted differences in the effective final-state nuclear absorption needed to fit the PHENIX dAu data. Taking advantage of our implementation of 2→2 kinematics, we have also computed the transverse momentum dependence of the nuclear modification factor, which cannot be predicted with the usual simplified kinematics. All the corresponding observables have been computed for CuCu and AuAu collisions and compared to the PHENIX and STAR data. Finally, we have extracted the effective nuclear absorption from the recent measurements of RCP in dAu collisions by the PHENIX collaboration.