Nuclear modification of forward $J/\psi$ production in proton-nucleus collisions at the LHC

We re-evaluate the nuclear suppression of forward $J/\psi$ production at high energy in the Color Glass Condensate framework. We use the collinear approximation for the projectile proton probed at large $x$ and an up to date dipole cross section fitted to HERA data to describe the target in proton-proton collisions. We show that using the Glauber approach to generalize the proton dipole cross section to the case of a nucleus target leads to a nuclear modification factor much closer to LHC data than previous estimates using the same framework.
Comment: 4 pages, 2 figures. Talk given by B.D. at the 7th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2015), 29 June - 3 July 2015, Montreal, Canada