Elliptic flow at SPS and RHIC: from kinetic transport to hydrodynamics
Abstract
Anisotropic transverse flow is studied in Pb+Pb and Au+Au collisions at SPS and RHIC energies. The centrality and transverse momentum dependence at midrapidity of the elliptic flow coefficient v_2 is calculated in the hydrodynamic and low density limits. Hydrodynamics is found to agree well with the RHIC data for semicentral collisions up to transverse momenta of 1-1.5 GeV/c, but it considerably overestimates the measured elliptic flow at SPS energies. The low density limit LDL is inconsistent with the measured magnitude of v_2 at RHIC energies and with the shape of its p_t-dependence at both RHIC and SPS energies. The success of the hydrodynamic model points to very rapid thermalization in Au+Au collisions at RHIC and provides a serious challenge for kinetic approaches based on classical scattering of on-shell particles.
Cite
@article{arxiv.hep-ph/0012137,
title = {Elliptic flow at SPS and RHIC: from kinetic transport to hydrodynamics},
author = {P. F. Kolb and P. Huovinen and U. Heinz and H. Heiselberg},
journal= {arXiv preprint arXiv:hep-ph/0012137},
year = {2009}
}
Comments
7 pages incl. 5 figures; submitted to Physics Letters B; Ref. 4 and a few typos corrected; no changes in contents