Towards an automated tool to evaluate the impact of the nuclear modification of the gluon density on quarkonium, D and B meson production in proton\u2013nucleus collisions

Abstract

We propose a simple and model-independent procedure to account for the impact of the nuclear modification of the gluon density as encoded in nuclear collinear PDF sets on two-to-two partonic hard processes in proton–nucleus collisions. This applies to a good approximation to quarkonium, D and B meson production, generically referred to mathcal {H}. Our procedure consists in parametrising the square of the parton scattering amplitude, {mathcal {A}}_{gg rightarrow {mathcal {H}} X} and constraining it from the proton–proton data. Doing so, we have been able to compute the corresponding nuclear modification factors for J/psi , Upsilon and D^0 as a function of y and P_T at sqrt{s_mathrm{NN}}=5 and 8 TeV in the kinematics of the various LHC experiments in a model independent way. It is of course justified since the most important ingredient in such evaluations is the probability of each kinematical configuration. Our computations for D mesons can also be extended to B meson production. To further illustrate the potentiality of the tool, we provide – for the first time – predictions for the nuclear modification factor for eta _c production in pPb collisions at the LHC.