Early-Stage Shear Viscosity far from Equilibrium via Holography

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, $\eta /s$. 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.

arXiv comment6 pages, 3 figures. Plenary Flash Talk given at the 28th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2019) Wuhan, China, November 4-9, 2019

References in corpus (13)

• Viscosity in Strongly Interacting Quantum Field Theories from Black Hole Physics
• New Forms of QCD Matter Discovered at RHIC
• Viscosity Information from Relativistic Nuclear Collisions: How Perfect is the Fluid Observed at RHIC?
• Viscosity Bound and Causality Violation
• Detailed measurement of the e+e- pair continuum in p+p and Au+Au collisions at sqrt(s_NN)=200 GeV and implications for direct photon production
• Fluid Dynamics far from Local Equilibrium
• Anisotropic flow in sqrt(s)=2.76 TeV Pb+Pb collisions at the LHC
• Transport Coefficients in Yang--Mills Theory and QCD
• Temperature dependence of shear viscosity of $SU(3)$--gluodynamics within lattice simulation
• Thermalization of the spectral function in strongly coupled two dimensional conformal field theories
• Higher harmonic non-linear flow modes of charged hadrons in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Shear transport far from equilibrium via holography
• Time-dependence of the holographic spectral function: Diverse routes to thermalisation

Cited by in corpus (3)

• A first estimate of $\eta /s$ in Au+Au reactions at E${}_{\mathrm{lab}}=1.23$ $A$GeV
• Shear transport far from equilibrium via holography
• Viscous effects of a hot QGP medium in time dependent magnetic field and their phenomenological significance