Collective flow in event-by-event partonic transport plus hydrodynamics hybrid approach

Rajeev S. Bhalerao, Amaresh Jaiswal, and Subrata Pal
Phys. Rev. C 92, 014903 – Published 10 July 2015

Abstract

Complete evolution of the strongly interacting matter formed in ultrarelativistic heavy-ion collisions is studied within a coupled Boltzmann and relativistic viscous hydrodynamics approach. For the initial nonequilibrium evolution phase, we employ a multiphase transport (AMPT) model that explicitly includes event-by-event fluctuations in the number and positions of the participating nucleons as well as of the produced partons with subsequent parton transport. The ensuing near-equilibrium evolution of quark-gluon and hadronic matter is modeled within the (2+1)-dimensional relativistic viscous hydrodynamics. We probe the role of parton dynamics in generating and maintaining the spatial anisotropy in the preequilibrium phase. Substantial spatial eccentricities ɛn are found to be generated in the event-by-event fluctuations in parton production from initial nucleon-nucleon collisions. For ultracentral heavy-ion collisions, the model is able to explain qualitatively the unexpected hierarchy of the harmonic flow coefficients vn(pT)(n=26) observed at energies currently available at the CERN Large Hadron Collider (LHC). We find that the results for vn(pT) are rather insensitive to the variation (within a range) of the time of switchover from AMPT parton transport to hydrodynamic evolution. The usual Grad and the recently proposed Chapman-Enskog-like (nonequilibrium) single-particle distribution functions are found to give very similar results for vn(n=24). The model describes well both the BNL Relativistic Heavy Ion Collider and LHC data for vn(pT) at various centralities, with a constant shear viscosity to entropy density ratio of 0.08 and 0.12, respectively. The event-by-event distributions of v2,3 are in good agreement with the LHC data for midcentral collisions. The linear response relation vn=knɛn is found to be true for n=2,3, except at large values of ɛn, where a larger value of kn is required, suggesting a small admixture of positive nonlinear response even for n=2,3.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
2 More
  • Received 27 February 2015

DOI:https://doi.org/10.1103/PhysRevC.92.014903

©2015 American Physical Society

Authors & Affiliations

Rajeev S. Bhalerao1, Amaresh Jaiswal2, and Subrata Pal3

  • 1Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
  • 2GSI, Helmholtzzentrum für Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt, Germany
  • 3Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 92, Iss. 1 — July 2015

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review C

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×