Charmonium dynamics in Au+Au collisions at sqrt(S)=200 GeV

TL;DR

This study compares two models of charmonium suppression in heavy-ion collisions at RHIC energies and finds that both models fail, indicating the dominance of partonic interactions in the quark-gluon plasma.

Contribution

The paper provides a comprehensive analysis showing that traditional hadronic models are insufficient to describe charmonium suppression at RHIC, emphasizing the importance of partonic interactions.

Findings

Both hadronic and QGP threshold models fail at RHIC energies.

Charm quark dynamics are dominated by strong partonic interactions.

Color screening alone cannot explain charmonium suppression.

Abstract

The formation and suppression dynamics of J/Psi, Chi_c and Psi-Prime mesons is studied within the HSD transport approach for Au+Au reactions at the top RHIC energy of sqrt(S)=200 GeV. Two prominent models, which have been discussed for more than a decade, are incorporated, i.e. the 'hadronic comover absorption and reformation' model as well as the 'QGP threshold' scenario, and compared to available experimental data. Our studies demonstrate that both scenarios - compatible with experimental observation at SPS energies - fail severely at RHIC energies. This combined analysis - together with the underestimation of charm elliptic flow - proves that the dynamics of c, c-bar quarks are dominated by partonic interactions in the strong QGP (sQGP) and can neither be modeled by 'hadronic' interactions nor described appropriately by color screening alone.