Resolving the J/\psi RHIC puzzles at LHC

TL;DR

This paper presents a model that explains charmonium suppression patterns observed at RHIC and predicts stronger suppression at LHC, incorporating nuclear shadowing, rapidity-dependent absorption, and recombination effects.

Contribution

The study introduces a comprehensive model combining shadowing, absorption, and recombination to explain charmonium suppression, successfully fitting RHIC data and predicting enhanced suppression at LHC.

Findings

Good agreement with RHIC data on rapidity and centrality distributions.

Model predicts stronger suppression at LHC than thermal models.

Inclusion of multiple effects explains observed suppression patterns.

Abstract

Experiments with gold-gold collisions at RHIC have revealed (i) stronger suppression of charmonium production at forward rapidity than at midrapidity and (ii) the similarity between the suppression degrees at RHIC and SPS energies. To describe these findings we employ the model that includes nuclear shadowing effects, calculated within the Glauber-Gribov theory, rapidity-dependent absorptive mechanism, caused by energy-momentum conservation, and dissociation and recombination of the charmonium due to interaction with co-moving matter. The free parameters of the model are tuned and fixed by comparison with experimental data at lower energies. A good agreement with the RHIC results concerning the rapidity and centrality distributions is obtained for both heavy Au+Au and light Cu+Cu colliding system. For pA and A+A collisions at LHC the model predicts stronger suppression of the charmonium and bottomonium yields in stark contrast to thermal model predictions.