Measurement of the azimuthal anisotropy of charged-particle production in Xe+Xe collisions at $\sqrt{s_{\mathrm{NN}}}=5.44$ TeV with the ATLAS detector

Abstract

This paper describes the measurements of flow harmonics $v_2$-$v_6$ in 3 $\mu {\mathrm{b}}^{-1}$ of Xe+Xe collisions at $\sqrt{s_{\mathrm{NN}}}=5.44$ TeV performed using the ATLAS detector at the LHC. Measurements of the centrality, multiplicity and $p_{\mathrm{T}}$ dependence of the $v_n$ obtained using two-particle correlations and the scalar product technique are presented. The measurements are also performed using a template-fit procedure, which was developed to remove non-flow correlations in small collision systems. This non-flow removal is shown to have a significant influence on the measured $v_n$ at high $p_{\mathrm{T}}$, especially in peripheral events. Comparisons of the measured $v_n$ with measurements in Pb+Pb collisions and $p$+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV are also presented. The $v_n$ values in Xe+Xe collisions are observed to be larger than those in Pb+Pb collisions for $n=2$, 3 and 4 in the most central events. However, with decreasing centrality or increasing harmonic order $n$, the $v_n$ values in Xe+Xe collisions become smaller than those in Pb+Pb collisions. The $v_n$ in Xe+Xe and Pb+Pb collisions are also compared as a function of the mean number of participating nucleons, $⟨N_{\text{part}}⟩$, and the measured charged-particle multiplicity in the detector. The $v_3$ values in Xe+Xe and Pb+Pb collisions are observed to be similar at the same $⟨N_{\text{part}}⟩$ or multiplicity, but the other harmonics are significantly different. Comparisons of the $v_n$ measurements with theoretical calculations are also made.

53 pages in total, author list starting page 37, 21 figures, 1 table, submitted to Phys. Rev. C. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2019-03/

References in corpus (7)

• Viscosity in Strongly Interacting Quantum Field Theories from Black Hole Physics
• Glauber Modeling in High Energy Nuclear Collisions
• Viscosity Information from Relativistic Nuclear Collisions: How Perfect is the Fluid Observed at RHIC?
• Relativistic viscous hydrodynamics, conformal invariance, and holography
• Dihadron azimuthal correlations in Au+Au collisions at sqrt(s_NN)=200 GeV
• Measurements of the Nuclear Modification Factor for Jets in Pb+Pb Collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV with the ATLAS Detector
• Measurement of flow harmonics with multi-particle cumulants in Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV with the ATLAS detector