$\eta /s$ and Phase Transitions

Abstract

We present a calculation of eta/s for the meson gas (zero baryon number), with the viscosity computed within unitarized NLO chiral perturbation theory, and confirm the observation that eta/s decreases towards the possible phase transition to a quark-gluon plasma/liquid. The value is somewhat higher than previously estimated in LO chi PT. We also examine the case of atomic Argon gas to check the discontinuity of eta/s across a first order phase transition. Our results suggest employing this dimensionless number, sometimes called KSS number (in analogy with other ratios in fluid mechanics such as Reynolds number or Prandtl number) to pin down the phase transition and critical end point to a cross-over in strongly interacting nuclear matter between the hadron gas and quark and gluon plasma/liquid.

Revised for PRD. Shorter (by one section) than first version. 6 pp, 4 figures

References in corpus (18)

• Viscosity in Strongly Interacting Quantum Field Theories from Black Hole Physics
• Holography and hydrodynamics: diffusion on stretched horizons
• Quark Mass and Flavour Dependence of the QCD Phase Transition
• On the Strongly-Interacting Low-Viscosity Matter Created in Relativistic Nuclear Collisions
• Has the QCD Critical Point been Signaled by Observations at RHIC ?
• Meson-meson scattering within one loop Chiral Perturbation Theory and its unitarization
• Measuring Shear Viscosity Using Transverse Momentum Correlations in Relativistic Nuclear Collisions
• The Shear Viscosity to Entropy Density Ratio of Trapped Fermions in the Unitarity Limit
• The electrical conductivity of a pion gas
• Is there a "most perfect fluid" consistent with quantum field theory?
• The Viscosity of Meson Matter
• Shear Viscosity to Entropy Density Ratio of QCD below the Deconfinement Temperature
• QCD Viscosity to Entropy Density Ratio in the Hadronic Phase
• Transport coefficients in large N_f gauge theories with massive fermions
• Comment on "Is There a "Most Perfect Fluid" Consistent with Quantum Field Theory?"
• Transport coefficients in Chiral Perturbation Theory
• Transport properties of a meson gas
• The ratio of viscosity to entropy density in a pion gas satisfies the KSS holographic bound

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• Bulk viscosity and the phase transition of the linear sigma model
• Shear viscosity $\eta$ to electrical conductivity ${\sigma }_{el}$ ratio for an anisotropic QGP
• Minimum of $\eta /s$ and the phase transition of the Linear Sigma Model in the large-N limit
• Particle production in Ultra-relativistic Heavy-Ion Collisions : A Statistical-Thermal Model Review
• van der Waals hadron resonance gas and QCD phase diagram
• Electrical conductivity of Hot and Dense QCD matter at RHIC BES energies: A Color String Percolation Approach
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• Electromagnetic effects in the pion dispersion relation at finite temperature
• Estimating transport coefficients of interacting pion gas with K-matrix cross sections
• Chemical nonequilibrium for interacting bosons: applications to the pion gas
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