Anisotropic flow of identified particles in Pb–Pb collisions at √SNN = 5.02 TeV

Redmer Alexander Bertens

doi:10.1051/epjconf/201817117002

Abstract

Anisotropic flow is sensitive to the shear (η/s) and bulk (ζ/s) viscosity of the quark-gluon plasma created in heavy-ion collisions, as well as the initial state of such collisions and hadronization mechanisms. In these proceedings, elliptic (υ2) and higher harmonic (υ3, υ4) flow coefficients of π±, K±, p(p) and the ϕ-meson, are presented for Pb—Pb collisions at the highest-ever center-of-mass energy of [see formula in PDF] = 5.02 TeV. Comparisons to hydrodynamic calculations (IP-Glasma, MUSIC, UrQMD) are shown to constrain the initial conditions and viscosity of the medium.

Highlights

Ultra-relativistic heavy-ion collisions are used to study the properties of the quark-gluon plasma (QGP), a state of deconfined quarks and gluons that is created at high energy densities and temperatures
Reference flow vectors Qn = j exp(inφ j) are measured in the Time Projection Chamber (TPC) and V0 detectors, where V0C is chosen as reference flow detector as it still has a high event plane resolution
A mass splitting of v2 of different particle species is found for pT < 2 GeV/c, which is indicative of strong radial flow [6]

Summary

Introduction

Ultra-relativistic heavy-ion collisions are used to study the properties of the quark-gluon plasma (QGP), a state of deconfined quarks and gluons that is created at high energy densities and temperatures. Harmonic coefficients vn – commonly called flow coefficients – are, in addition to being a probe for η/s and ζ/s, sensitive to the initial state of the system, freeze-out conditions, hadronization mechanisms, and the lifetime of the system. The V0 scintillator detectors, located at 2.8 < η < 5.1 (V0A) and -3.7 < η < -1.7 (V0C), are used for centrality determination, and reconstruction of the QVn 0 vectors (see Eq 2).

Results

Conclusion