Forward and midrapidity charmonium production at RHIC

TL;DR

This paper models $J/a$ production at RHIC using a rate-equation approach, explaining rapidity-dependent suppression and calculating related charmonium ratios, with results compared to experimental data.

Contribution

It introduces a rate-equation model that accounts for direct production and regeneration of charmonium, providing insights into rapidity-dependent suppression at RHIC.

Findings

Stronger suppression at forward rapidity explained by less regeneration and more cold nuclear matter effects.

Calculated $a_c$/$J/a$ and $a'$/$J/a$ ratios align qualitatively with experimental observations.

Model reproduces key features of charmonium production and suppression at RHIC.

Abstract

$J/\psi$ production at forward and midrapidity at the Relativistic Heavy-Ion Collider (RHIC) is calculated within a previously constructed rate-equation approach accounting for both direct production and regeneration from $c$ and $\bar c$. The results are compared to experimental data. The observed stronger suppression at forward rapidity can be qualitatively explained by a smaller statistical regeneration component together with stronger cold nuclear matter induced suppression compared to midrapidity. The $\chi_c$ over $J/\psi$ ratio and $\psi'$ over $J/\psi$ ratio are also calculated.