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arXiv · 2010.10575

Early-Stage Shear Viscosity far from Equilibrium via Holography

Michael F. Wondrak·Matthias Kaminski·Marcus Bleicher
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Abstract

Shear viscosity is a crucial property of QCD matter which determines the collective behavior of the the quark-gluon plasma (QGP) in ultrarelativistic heavy-ion collisions. Extending the near-equilibrium, high-precision investigations in theory and experiment, we take into account the fact that, in a collision, the QGP is generated far from equilibrium. We use the AdS/CFT correspondence to study a strongly coupled plasma and find a significant impact on the ratio of shear viscosity to entropy density, $η/s$. In particular, we investigate the initial heating phase and find a decrease reaching down to below 60% followed by an overshoot to 110% of the near-equilibrium value. This finding might be highly relevant for the extraction of transport coefficients from anisotropic flow measurements at RHIC and LHC.

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Michael F. Wondrak, Matthias Kaminski, Marcus Bleicher. 2020-10-20. Early-Stage Shear Viscosity far from Equilibrium via Holography. https://doi.org/10.1016/j.nuclphysa.2020.121880

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