Shear and bulk viscosities of the gluon plasma across the transition temperature from lattice QCD

Abstract

We investigate the temperature dependence of the shear viscosity ($\eta$) and bulk viscosity ($\zeta$) of the gluon plasma using lattice QCD over the range 0.76--2.25$T_c$, extending from below the transition temperature $T_c$ across the transition region and into the deconfined phase. At each temperature, we employ three large, fine lattices, which enables controlled continuum extrapolations of the energy-momentum tensor correlators. Using gradient flow together with a recently developed blocking technique, we achieve percent-level precision for these correlators, providing strong constraints for a model-based spectral analysis. Since the inversion to real-time information is intrinsically ill posed, we extract viscosities by fitting spectral functions whose ultraviolet behavior is matched to the best available perturbative result, while the infrared region is described by a Lorentzian transport peak. The dominant modeling uncertainty associated with the transport peak width is bracketed by varying it over a physically motivated range set by thermal scales. We find that the shear-viscosity-to-entropy-density ratio, $\eta /s$, exhibits a minimum near the transition temperature $T_c$ and increases for $T>T_c$, whereas the bulk-viscosity-to-entropy-density ratio, $\zeta /s$, decreases monotonically over the entire temperature range studied.

16 pages, 10 figures

References in corpus (26)

• Viscosity in Strongly Interacting Quantum Field Theories from Black Hole Physics
• Viscosity Information from Relativistic Nuclear Collisions: How Perfect is the Fluid Observed at RHIC?
• Energy Loss and Flow of Heavy Quarks in Au+Au Collisions at sqrt(s_NN) = 200 GeV
• 200 A GeV Au+Au collisions serve a nearly perfect quark-gluon liquid
• Perturbative analysis of the gradient flow in non-abelian gauge theories
• On the Strongly-Interacting Low-Viscosity Matter Created in Relativistic Nuclear Collisions
• A calculation of the bulk viscosity in SU(3) gluodynamics
• Infinite N phase transitions in continuum Wilson loop operators
• Has the QCD Critical Point been Signaled by Observations at RHIC ?
• The centrality dependence of elliptic flow, the hydrodynamic limit, and the viscosity of hot QCD
• Bulk viscosity of QCD matter near the critical temperature
• Perturbative QCD Calculations of Elliptic Flow and Shear Viscosity in Au+Au Collisions at $\sqrt{s_{NN}}=200$ GeV
• Critical point and scale setting in SU(3) plasma: An update
• A local factorization of the fermion determinant in lattice QCD
• The perturbative QCD gradient flow to three loops
• Thermal quarkonium physics in the pseudoscalar channel
• Correlations of Energy-Momentum Tensor via Gradient Flow in SU(3) Yang-Mills Theory at Finite Temperature
• Energy-momentum tensor on the lattice: non-perturbative renormalization in Yang--Mills theory
• HotQCD on Multi-GPU Systems
• The sphaleron rate from Euclidean lattice correlators: an exploration
• SIMULATeQCD: A simple multi-GPU lattice code for QCD calculations
• Viscosity of pure-glue QCD from the lattice
• Sparse modeling approach to obtaining the shear viscosity from smeared correlation functions
• Lattice $B$-field correlators for heavy quarks
• Lattice QCD noise reduction for bosonic correlators through blocking
• Four-dimensional factorization of the fermion determinant in lattice QCD