arXiv:1001.2912v2 [hep-ph] 27 Jan 2010 Dependence of elliptic flow on number of parton degrees of freedom Zhe Xu ∗ 1, 2 and Carsten Greiner † 2 $^{1}$Frankfurt Institute for Advanced Studies, Ruth-Moufang-Strasse 1, D-60438 Frankfurt am Main, Germany $^{2}$Institut f¨ ur Theoretische Physik, Goethe-Universit¨ at Frankfurt, Max-von-Laue-Strasse 1, D-60438 Frankfurt am Main, Germany (Dated: December 3, 2018) We calculate the elliptic flow parameter v$_{2}$ for Au+Au collisions at √ s$_{NN}$ = 200 GeV employing the parton cascade BAMPS (Boltzmann Approach of Multiparton Scatterings). Besides gluon interactions including the bremsstrahlung process, interactions with quarks are considered in an effective, but approximate way to investigate the dependence of the collective flow on the number of parton degrees of freedom. We find that v$_{2}$ as a function of the transverse momentum p$_{T}$ is sensitive to the number of parton degrees of freedom, whereas the p$_{T}$ averaged v$_{2}$ does not. When including quarks, v$_{2}$ ( p$_{T}$ ) shifts to lower p$_{T}$ , the parton transverse momentum spectra become softer and the mean parton transverse momenta decrease. PACS numbers: 25.75.-q, 25.75.Ld, 12.38.Mh, 24.10.Lx Abstract ∗ xu@th.physik.uni-frankfurt.de † carsten.greiner@th.physik.uni-frankfurt.de 1