Measurement of higher harmonic flow coefficients of identified hadrons in Pb-Pb collisions at = 2.76 TeV

Abstract

The latest ALICE results on the centrality and transverse momentum dependence of v2, v3, v4 and v5 for π±, K± and p() in Pb–Pb collisions at = 2.76 TeV are presented. The flow coefficients exhibit a clear mass ordering for pT < 2.5 GeV/c for all harmonics. For transverse momentum values larger than about 3 GeV/c, mesons exhibit distinctively lower flow values compared to baryons, suggesting that coalescence might be the relevant particle production mechanism in this region. The experimental data for pT < 2.5 GeV/c are described fairly well by the hydrodynamical model iEBE-VISHNU, which models the hydrodynamical expansion of the fireball using a value of η/s = 0.08, coupled to a hadronic cascade model (UrQMD). Finally, A Multi-Phase Transition Model (AMPT) highlights the significant contribution of the hadronic rescattering phase and of coalescence as the dominant particle production mechanism to the mass ordering at low pT and the baryon-meson grouping at intermediate pT, respectively.