Multiplicity scaling in ideal and viscous hydrodynamics
By Huichao Song, Ulrich Heinz. 2008
185 citations recorded by the source corpus.
Using numerical results from ideal and viscous relativistic hydrodynamic simulations with three different equations of state, for Au+Au and Cu+Cu collisions at different centralities and initial energy densities, we explore the dependence of the eccentricity-scaled elliptic flow, v{sub 2}/{epsilon}, and the produced entropy fraction, {delta}S/S{sub 0}, on the final charged hadron multiplicity density dN{sub ch}/dy per unit transverse overlap area S,(1/S)dN{sub ch}/dy. The viscous hydrodynamic simulations are performed with two different versions of the Israel-Stewart kinetic evolution equations, and in each case we investigate the dependence of the physical observables on the kinetic relaxation time. We find approximate scaling of v{sub 2}/{epsilon} and {delta}S/S{sub 0} with (1/S)dN{sub ch}/dy, with scaling functions that depend on the EOS and, in particular, on the value of the specific shear viscosity {eta}/s. Small scaling violations are seen even in ideal hydrodynamics, caused by a breaking of the scale invariance of ideal fluid dynamics by the freeze-out condition. Viscous hydrodynamics shows somewhat larger scale-breaking effects that increase with increasing {eta}/s and decreasing system size and initial energy density. We propose to use precision studies of these scaling violations to help constrain the shear viscosity {eta}/s of the quark-gluon plasma created in relativistic heavy ion collisions.
Subfields: Applied Mathematics, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/f4af3687215332f109719988423337f702c8661c
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In Applied Mathematics
In Nuclear and High Energy Physics
- Paul Romatschke
- P. Kovtun
- Chun Shen
- Huichao Song
- Jonah E. Bernhard
- Guy D. Moore
- Ulrich Heinz
- Steffen A. Bass
Citations in the corpus
- 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.”
- Stickiness of sound: An absolute lower limit on viscosity and the breakdown of second-order relativistic hydrodynamics (2011, background): “[26] H.”