• S. Acharya
  • J. Adam
  • D. Adamová
  • J. Adolfsson
  • M. M. Aggarwal
  • G. Aglieri Rinella
  • M. Agnello
  • N. Agrawal
  • Z. Ahammed
  • N. Ahmad
  • S. U. Ahn
  • S. Aiola
  • A. Akindinov
  • M. Al-Turany
  • S. N. Alam
  • J. L.B. Alba
  • D. S.D. Albuquerque
  • D. Aleksandrov
  • B. Alessandro
  • R. Alfaro Molina
  • A. Alici
  • A. Alkin
  • J. Alme
  • T. Alt
  • L. Altenkamper
  • C. Alves Garcia Prado
  • C. Andrei
  • D. Andreou
  • H. A. Andrews
  • A. Andronic
  • V. Anguelov
  • C. Anson
  • T. Antičić
  • F. Antinori
  • P. Antonioli
  • R. Anwar
  • L. Aphecetche
  • H. Appelshäuser
  • S. Arcelli
  • R. Arnaldi
  • O. W. Arnold
  • I. C. Arsene
  • M. Arslandok

The correlations between event-by-event fluctuations of anisotropic flow harmonic amplitudes have been measured in Pb-Pb collisions at sNN=2.76 TeV with the ALICE detector at the Large Hadron Collider. The results are reported in terms of multiparticle correlation observables dubbed symmetric cumulants. These observables are robust against biases originating from nonflow effects. The centrality dependence of correlations between the higher order harmonics (the quadrangular v4 and pentagonal v5 flow) and the lower order harmonics (the elliptic v2 and triangular v3 flow) is presented. The transverse momentum dependences of correlations between v3 and v2 and between v4 and v2 are also reported. The results are compared to calculations from viscous hydrodynamics and a multiphase transport (AMPT) model calculations. The comparisons to viscous hydrodynamic models demonstrate that the different order harmonic correlations respond differently to the initial conditions and the temperature dependence of the ratio of shear viscosity to entropy density (η/s). A small average value of η/s is favored independent of the specific choice of initial conditions in the models. The calculations with the AMPT initial conditions yield results closest to the measurements. Correlations among the magnitudes of v2, v3, and v4 show moderate pT dependence in midcentral collisions. This might be an indication of possible viscous corrections to the equilibrium distribution at hadronic freeze-out, which might help to understand the possible contribution of bulk viscosity in the hadronic phase of the system. Together with existing measurements of individual flow harmonics, the presented results provide further constraints on the initial conditions and the transport properties of the system produced in heavy-ion collisions.

Original languageEnglish
Article number024906
Number of pages23
JournalPhysical Review C
Volume97
Issue number2
DOIs
StatePublished - 12 Feb 2018

    Research areas

  • HEAVY-ION COLLISIONS, QUARK-GLUON PLASMA, RELATIVISTIC NUCLEAR COLLISIONS, MONTE-CARLO, AZIMUTHAL ANISOTROPY, TRANSVERSE-MOMENTUM, COLLECTIVE FLOW, ELLIPTIC FLOW, MODEL, VISCOSITY

    Scopus subject areas

  • Nuclear and High Energy Physics

ID: 15731225