Causal viscous hydrodynamics in 2+1 dimensions for relativistic heavy-ion collisions

By Huichao Song, Ulrich Heinz. 2007

361 citations recorded by the source corpus.

We explore the effects of shear viscosity on the hydrodynamic evolution and final hadron spectra of Cu + Cu collisions at ultrarelativistic collision energies, using the newly developed (2 + 1)-dimensional viscous hydrodynamic code VISH2+1. Based on the causal Israel-Stewart formalism, this code describes the transverse evolution of longitudinally boost-invariant systems without azimuthal symmetry around the beam direction. Shear viscosity is shown to decelerate the longitudinal and accelerate the transverse hydrodynamic expansion. For fixed initial conditions, this leads to a longer quark-gluon plasma (QGP) lifetime, larger radial flow in the final state, and flatter transverse momentum spectra for the emitted hadrons compared to ideal fluid dynamic simulations. We find that the elliptic flow coefficient v{sub 2} is particularly sensitive to shear viscosity: even the lowest value allowed by the AdS/CFT conjecture {eta}/s{>=}1/4{pi} suppresses v{sub 2} enough to have significant consequences for the phenomenology of heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC). A comparison between our numerical results and earlier analytic estimates of viscous effects within a blast-wave model parametrization of the expanding fireball at freeze-out reveals that the full dynamical theory leads to much tighter constraints for the specific shear viscosity {eta}/s, thereby supporting the notion thatmore » the quark-gluon plasma created at RHIC exhibits almost 'perfect fluidity.'.« less

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/34888804dde9f02aa933486dfa68cdab45af8f59

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In Nuclear and High Energy Physics

Citations in the corpus

Causal hydrodynamics of gauge theory plasmas from AdS/CFT duality (2007, background): “For example, a number of groups recently reported the results of the (2 + 1)-dimensional numerical simulations of causal hydrodynamics [12, 13, 14, 15, 16].”
Relativistic viscous fluid dynamics and non-equilibrium entropy (2009, background): “ients from lattice Quantum-Chromodynamics [32]. Also, knowing the structure of the viscous ﬂuid dynamic equations may be required to extend conformal ﬂuid dynamics simulations of heavy-ion collisions [33, 34, 35, 36] to reliably include eﬀects from bulk viscosity. It could furthermore help to clarif”
The iEBE-VISHNU code package for relativistic heavy-ion collisions (2014, methodology): “VISHNew was tested against semi-analytical solutions derived based on Gubser’s flow.”
Properties of hot and dense matter from relativistic heavy ion collisions (2015, methodology): “Determinations of η/s at RHIC based on viscous fluid dynamics were obtained in [35, 36, 208].”