Correlated Event-by-Event Fluctuations of Flow Harmonics in Pb-Pb Collisions at sNN =2.76 TeV

Research output: Contribution to journalArticle


We report the measurements of correlations between event-by-event fluctuations of amplitudes of anisotropic flow harmonics in nucleus-nucleus collisions, obtained for the first time using a new analysis method based on multiparticle cumulants in mixed harmonics. This novel method is robust against systematic biases originating from nonflow effects and by construction any dependence on symmetry planes is eliminated. We demonstrate that correlations of flow harmonics exhibit a better sensitivity to medium properties than the individual flow harmonics. The new measurements are performed in Pb-Pb collisions at the center-of-mass energy per nucleon pair of sNN=2.76 TeV by the ALICE experiment at the Large Hadron Collider. The centrality dependence of correlation between event-by-event fluctuations of the elliptic v2 and quadrangular v4 flow harmonics, as well as of anticorrelation between v2 and triangular v3 flow harmonics are presented. The results cover two different regimes of the initial state configurations: geometry dominated (in midcentral collisions) and fluctuation dominated (in the most central collisions). Comparisons are made to predictions from Monte Carlo Glauber, viscous hydrodynamics, ampt, and hijing models. Together with the existing measurements of the 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. © 2016 CERN.


External organisations
  • Czech Technical University in Prague
  • Nuclear Physics Institute, ASCR
  • Panjab University
  • CERN
  • Polytechnic University of Turin
  • Indian Institute of Technology, Bombay
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Subatomic Physics


  • Colliding beam accelerators, Heavy ions, Lead, Tellurium compounds, Anisotropic flows, Center-of-mass energies, Event-by-event fluctuations, Heavy ion collision, Initial conditions, Large Hadron Collider, Nucleus-nucleus collision, Pb-Pb collisions, Harmonic analysis
Original languageEnglish
Article number182301
JournalPhysical Review Letters
Issue number18
Publication statusPublished - 2016
Publication categoryResearch

Bibliographic note

Cited By :8 Export Date: 14 July 2017