Journal article

Publication year: 2008

Pages: 79-104

Journal: Nuclear Physics A: Nuclear and Hadronic Physics

Volume number: 807

Issue number: 1-2

ISSN: 0375-9474

eISSN: 1873-1554

Open access status: Green

DOI Link: https://doi.org/10.1016/j.nuclphysa.2008.03.016

Publisher: Elsevier

Abstract: 
Within the Hadron-String Dynamics (HSD) transport approach we study the suppression pattern of charmonia at RHIC with respect to centrality and rapidity employing various model concepts, such as variants of the 'comover absorption' model or the 'charmonium melting' scenario. We find that especially the ratio of the forward to mid-rapidity nuclear modification factors of J/psi (R-AA(forward) (J/psi)/R-AA(mid) (J/psi)) cannot be explained by the interactions with 'formed' comoving mesons or by the 'color screening mechanism' alone. Only when incorporating interactions of the c or (c) over bar quark with a pre-hadronic medium satisfactory results are obtained. A detailed comparison to the PHENIX data demonstrates that non-hadronic interactions are mandatory to describe the narrowing of the J/psi rapidity distribution from pp to central Au + Au collisions. The psi' to J/psi ratio is found to be crucial in disentangling the different charmonium absorption scenarios, especially in the RHIC energy range. Furthermore, a comparison of the transport calculations to the statistical model of Gorenstein and Gazdzicki as well as the statistical hadronization model of Andronic et al. shows differences in the energy dependence as well as centrality dependence of the J/psi to pion ratio which may be exploited experimentally to disentangle different concepts. We find additionally that the collective flow of charm in the HSD transport appears compatible with the data at SPS energies but substantially underestimates the data at top RHIC energies, such that the large elliptic flow upsilon(2) of charm seen experimentally has to be attributed to early interactions of non-hadronic degrees of freedom. (C) 2008 Elsevier B.V. All rights reserved.

Harvard Citation style: Linnyk, O., Bratkovskaya, E. and Cassing, W. (2008) Evidence for non-hadronic interactions of charm degrees of freedom in heavy-ion collisions at relativistic energies, Nuclear Physics A: Nuclear and Hadronic Physics, 807(1-2), pp. 79-104. https://doi.org/10.1016/j.nuclphysa.2008.03.016

APA Citation style: Linnyk, O., Bratkovskaya, E., & Cassing, W. (2008). Evidence for non-hadronic interactions of charm degrees of freedom in heavy-ion collisions at relativistic energies. Nuclear Physics A: Nuclear and Hadronic Physics. 807(1-2), 79-104. https://doi.org/10.1016/j.nuclphysa.2008.03.016