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

TL;DR

This paper re-evaluates the nuclear suppression of forward J/ψ production in proton-nucleus collisions at the LHC using the Color Glass Condensate framework, improving agreement with experimental data.

Contribution

It introduces an updated approach to model nuclear effects in J/ψ production, using a Glauber extension that aligns theoretical predictions more closely with LHC observations.

Findings

Glauber approach improves nuclear modification factor predictions

Updated dipole cross section fits HERA data better

Results align more closely with LHC experimental data

Abstract

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.