Initial condition for hydrodynamics, partonic free streaming, and the uniform description of soft observables at RHIC

dc.creatorBroniowski, Wojciech
dc.creatorChojnacki, Mikolaj
dc.creatorFlorkowski, Wojciech
dc.creatorKisiel, Adam
dc.date2008-01-28
dc.date.accessioned2026-07-07T11:55:38Z
dc.date.available2026-07-07T11:55:38Z
dc.descriptionWe investigate the role of the initial condition used for the hydrodynamic evolution of the system formed in ultra-relativistic heavy-ion collisions and find that an appropriate choice motivated by the models of early-stage dynamics, specifically a simple two-dimensional Gaussian profile, leads to a uniform description of soft observables measured in the Relativistic Heavy-Ion Collider (RHIC). In particular, the transverse-momentum spectra, the elliptic-flow, and the Hanbury-Brown--Twiss correlation radii, including the ratio R_out/R_side as well as the dependence of the radii on the azimuthal angle (azHBT), are properly described. We use the perfect-fluid hydrodynamics with a realistic equation of state based on lattice calculations and the hadronic gas at high and low temperatures, respectively. We also show that the inclusion of the partonic free-streaming in the early stage allows to delay the start of the hydrodynamical description to comfortable times of the order of 1 fm/c. Free streaming broadens the initial energy-density profile, but generates the initial transverse and elliptic flow. The data may be described equally well when the hydrodynamics is started early, or with a delay due to partonic free-streaming.
dc.description4 pages, 4 figures
dc.identifierhttps://arxiv.org/abs/0801.4361
dc.identifierhttp://arxiv.org/abs/0801.4361
dc.identifierPhys.Rev.Lett.101:022301,2008
dc.identifierdoi:10.1103/PhysRevLett.101.022301
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/205309
dc.subjectNuclear Theory
dc.subjectHigh Energy Physics - Phenomenology
dc.subjectNuclear Experiment
dc.titleInitial condition for hydrodynamics, partonic free streaming, and the uniform description of soft observables at RHIC
dc.typetext

Files

Collections