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arXiv · 1011.2783

200 A GeV Au+Au collisions serve a nearly perfect quark-gluon liquid

Huichao Song·Steffen A. Bass·Ulrich W. Heinz·Tetsufumi Hirano·Chun Shen
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Abstract

The specific shear viscosity (eta/s)_QGP of a Quark-Gluon-Plasma (QGP) at temperatures T_c < T < 2T_c is extracted from the centrality dependence of the eccentricity-scaled elliptic flow measured in ultra-relativistic heavy-ion collisions. Coupling viscous fluid dynamics for the QGP with a microscopic transport model for hadronic freeze-out we find that the eccentricity-scaled elliptic flow is a universal function of charged multiplicity per unit overlap area, (1/S)(dN_ch/dy), that depends only on the viscosity but not on the model used for computing the initial fireball eccentricity. Comparing with measurements we find 1 < (4pi)(eta/s)_QGP < 2.5 where the uncertainty range is dominated by model uncertainties for the eccentricity values used to normalize the measured elliptic flow.

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Huichao Song, Steffen A. Bass, Ulrich W. Heinz, Tetsufumi Hirano, Chun Shen. 2011-04-21. 200 A GeV Au+Au collisions serve a nearly perfect quark-gluon liquid. https://doi.org/10.1103/physrevlett.106.192301

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