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arXiv · 0704.3553

The centrality dependence of elliptic flow, the hydrodynamic limit, and the viscosity of hot QCD

Hans-Joachim Drescher·Adrian Dumitru·Clement Gombeaud·Jean-Yves Ollitrault
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Abstract

We show that the centrality and system-size dependence of elliptic flow measured at RHIC are fully described by a simple model based on eccentricity scaling and incomplete thermalization. We argue that the elliptic flow is at least 25% below the (ideal) ``hydrodynamic limit'', even for the most central Au-Au collisions. This lack of perfect equilibration allows for estimates of the effective parton cross section in the Quark-Gluon Plasma and of its viscosity to entropy density ratio. We also show how the initial conditions affect the transport coefficients and thermodynamic quantities extracted from the data, in particular the viscosity and the speed of sound.

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Hans-Joachim Drescher, Adrian Dumitru, Clement Gombeaud, Jean-Yves Ollitrault. 2007-06-28. The centrality dependence of elliptic flow, the hydrodynamic limit, and the viscosity of hot QCD. https://doi.org/10.1103/physrevc.76.024905

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