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–nucleus collisions

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 H . Our procedure consists in parametrising the square of the parton scattering amplitude, A g g → 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 / ψ , Υ and D 0 as a function of y and P T at s 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 η c production in p Pb collisions at the LHC.