Charmonium suppression by gluon bremsstrahlung in p-A and A-B collisions

TL;DR

This paper investigates how prompt gluons produced via bremsstrahlung in nuclear collisions contribute to charmonium suppression, providing a quantitative model that aligns with experimental data.

Contribution

It introduces a perturbative calculation of prompt gluon spectra and inelastic cross sections, offering a new mechanism for charmonium suppression in nuclear collisions.

Findings

Prompt gluons significantly contribute to charmonium suppression.

The model quantitatively fits experimental data with minimal parameter adjustment.

Gluon-induced suppression explains observed dependencies on transverse energy.

Abstract

Prompt gluons are an additional source for charmonium suppression in nuclear collisions, in particular for nucleus-nucleus collisions. These gluons are radiated as bremsstrahlung in N-N collisions and interact inelastically with the charmonium states while the nuclei still overlap. The spectra and mean number <n_g> of the prompt gluons are calculated perturbatively and the gluon-Psi inelastic cross section is estimated. The integrated cross sections for AB --> J/Psi (Psi')X for p-A and A-B collisions and the dependence on transverse energy for S-U and Pb-Pb can be described quantitatively with some adjustment of one parameter <n_g>\sigma(gPsi).