Suppression of elliptic flow in a minimally viscous quark-gluon plasma
By Huichao Song, Ulrich Heinz. 2007
296 citations recorded by the source corpus.
The success of the hydrodynamic model in describing the bulk of hadron production in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC) [1] has led to a paradigmatic shift in our view of the quark-gluon plasma (QGP): Instead of behaving like a gas of weakly interacting quarks and gluons [2], as naively expected on the basis of asymptotic freedom in QCD, its collective properties rather reflect those of a “perfect liquid” with (almost) vanishing viscosity. However, due to quantum mechanical uncertainty no fluid can have exactly zero viscosity [3], and recent work [4] on strongly coupled gauge field theories, based on techniques exploiting the AdS/CFT correspondence, suggests an absolute lower limit for the ratio of shear viscosity η to entropy density s: η/s ≥ ~/4π. This raises the interesting question how close to this limit the actual value of the shear viscosity of the QGP created at RHIC is. Answering this question requires hydrodynamic simulations for relativistic viscous fluids in which the ratio η/s enters as a parameter. To study the anisotropic (“elliptic”) collective flow in non-central heavy-ion collisions, from which limits on η/s can be extracted [5], requires a code that evolves the hydrodynamic fields at least in the two dimensions transverse to the heavy-ion beam. In this Letter we present our first results from such simulations [6]; a longer paper with a discussion of all technical details of our approach is in preparation [7].
Subfields: Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/f692b93230915fdb830fd8936e5d9e3d0d58bf1b
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In Nuclear and High Energy Physics
Citations in the corpus
- Transport properties of the quark-gluon plasma (2011, methodology): “data to the dependence of v2 on this parameter [10,11,12], as illustrated in Fig.”
- Effect of curvature squared corrections in AdS on the viscosity of the dual gauge theory (2007, background): “In addition to these fundamental questions, the results may turn relevant to the quark-gluon plasma, whose viscosity is measured to be close to the bound [17] (and possibly violates the bound [18, 19]).”
- Relativistic Fluid Dynamics in and out of Equilibrium (2017, background): “No constraints on viscosity value • 2007: Theory of relativistic viscous fluid dynamics set up as an effective field theory of long-lived, long-wave excitations by two groups [28, 29] • 2007: 2+1 relativistic viscous fluid modeling of elliptic flow in heavyion collisions by several groups [30–33].”