Hydrodynamic flow in heavy-ion collisions with large hadronic viscosity

Abstract

Using the (2+1)-dimensional viscous hydrodynamic code VISH2+1 with a temperature dependent specific shear viscosity (eta/s)(T), we present a detailed study of the influence of a large hadronic shear viscosity and its corresponding relaxation time tau_pi on the transverse momentum spectra and elliptic flow of hadrons produced in 200 A GeV Au+Au collisions. Although theory, in principle, predicts a well-defined relation T*tau_pi = kappa(T)*(eta/s)(T), the precise form of kappa(T) for the matter created in relativistic heavy-ion collisions is not known. For the popular choice kappa=3 the hadron spectra are found to be insensitive to a significant rise of eta/s in the hadronic stage, whereas their differential elliptic flow v_2(p_T) is strongly suppressed by large hadronic viscosity. The large viscous effects on v_2 are strongly reduced if (as theoretically expected) kappa(T) is allowed to grow with decreasing temperature in the hadronic stage. This implies that, until reliable calculations of kappa(T) become available, an extraction of the hadronic shear viscosity from a comparison between VISH2+1 and a microscopic hadron cascade or experimental data requires a simultaneous fit of (eta/s)(T) and kappa(T).

12 pages, 10 figures, submitted to Physical Review C. Parts of abstract and introduction, as well as all of Sec. VI, have been rewritten for v2. v2 uses a more realistic toy model for kappa(T) than v1, and all results obtained with the earlier model have been replaced (but are still available at http://arxiv.org/abs/1101.3703v1). No change to conclusions

References in corpus (16)

• Nonlinear Fluid Dynamics from Gravity
• Relativistic viscous hydrodynamics, conformal invariance, and holography
• On the Strongly-Interacting Low-Viscosity Matter Created in Relativistic Nuclear Collisions
• Suppression of elliptic flow in a minimally viscous quark-gluon plasma
• Dissipative Hydrodynamics and Heavy Ion Collisions
• Dissipative relativistic fluid dynamics: a new way to derive the equations of motion from kinetic theory
• Effects of fluctuations on the initial eccentricity from the Color Glass Condensate in heavy ion collisions
• Viscous QCD matter in a hybrid hydrodynamic+Boltzmann approach
• The eccentricity in heavy-ion collisions from Color Glass Condensate initial conditions
• Second order hydrodynamic coefficients from kinetic theory
• Systematic parameter study of hadron spectra and elliptic flow from viscous hydrodynamic simulations of Au+Au collisions at sqrt(s_NN) = 200 GeV
• Causal Viscous Hydrodynamics for Central Heavy-Ion Collisions
• Causal Viscous Hydrodynamics for Central Heavy-Ion Collisions II: Meson Spectra and HBT Radii
• Transport Coefficients of Non-Newtonian Fluid and Causal Dissipative Hydrodynamics
• Bulk Viscosity and Relaxation Time of Causal Dissipative Relativistic Fluid Dynamics
• Shear viscosity coefficient and relaxation time of causal dissipative hydrodynamics in QCD

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