CERN Accelerating science

Article
Report number	arXiv:1805.01604
Title	Matching the non-equilibrium initial stage of heavy ion collisions to hydrodynamics with QCD kinetic theory
Author(s)	Kurkela, Aleksi (CERN ; Stavanger U.) ; Mazeliauskas, Aleksas (U. Heidelberg, ITP ; Stony Brook U.) ; Paquet, Jean-François (Duke U. ; Stony Brook U.) ; Schlichting, Sören (Washington U., Seattle) ; Teaney, Derek (Stony Brook U.)
Publication	2019-03-28
Imprint	2018-05-04
Number of pages	7
Note	7 pages, 4 figures, v2: typos corrected and minor changes, version accepted for publication in Phys. Rev. Lett., see also our companion paper arXiv:1805.00961 for the extensive details, for the code of linear kinetic theory propagator KoMPoST used for this study see https://github.com/KMPST/KoMPoST ; v3 updated references, published version
In:	Phys. Rev. Lett. 122 (2019) 122302
DOI	10.1103/PhysRevLett.122.122302
Subject category	nucl-th ; Nuclear Physics - Theory ; hep-ph ; Particle Physics - Phenomenology
Abstract	High-energy nuclear collisions produce a nonequilibrium plasma of quarks and gluons which thermalizes and exhibits hydrodynamic flow. There are currently no practical frameworks to connect the early particle production in classical field simulations to the subsequent hydrodynamic evolution. We build such a framework using nonequilibrium Green's functions, calculated in QCD kinetic theory, to propagate the initial energy-momentum tensor to the hydrodynamic phase. We demonstrate that this approach can be easily incorporated into existing hydrodynamic simulations, leading to stronger constraints on the energy density at early times and the transport properties of the QCD medium. Based on (conformal) scaling properties of the Green's functions, we further obtain pragmatic bounds for the applicability of hydrodynamics in nuclear collisions.
Copyright/License	preprint: (License: arXiv nonexclusive-distrib 1.0) Publication: © 2019-2025 authors

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