Inclusive production of $J/\psi$ mesons at forward rapidity can be an important probe of saturation dynamics. We study this process in the Color Glass Condensate framework, in which a large x gluon from the proton probe splits into a quark pair and eikonally interacts with the target proton or nucleus probed at small x. We show that relying on the optical Glauber model to obtain the dipole cross section of the nucleus from the one of the proton fitted to HERA DIS data leads to a smaller nuclear suppression than in the first study of this process in this formalism and a better agreement with experimental data. We then study the centrality dependence of our model and extend our calculation to backward rapidities using nuclear parton distribution functions. Finally, by integrating over the phase space of one of the produced quarks and convoluting with fragmentation functions, we study the consequences for the nuclear modification of forward D-meson production in the same kinematics.
We present a study of forward $J/\psi$ and D-meson production in high energy proton-nucleus collisions at the LHC using the Color Glass Condensate formalism.