This paper describes the measurements of flow harmonics υ2–υ6 in 3 µb−1 of Xe+Xe collisions at √sNN = 5.44 TeV performed using the ATLAS detector at the LHC. Measurements of the centrality, multiplicity and pT dependence of the υn 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 υn at high pT, especially in peripheral events. Comparisons of the measured υn with measurements in Pb+Pb collisions and p+Pb collisions at √sNN = 5.02 TeV are also presented. The υn 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 υn values in Xe+Xe collisions become smaller than those in Pb+Pb collisions. The υn in Xe+Xe and Pb+Pb collisions are also compared as a function of the mean number of participating nucleons, 〈Npart〉, and the measured charged-particle multiplicity in the detector. The υ3 values in Xe+Xe and Pb+Pb collisions are observed to be similar at the same 〈Npart〉 or multiplicity, but the other harmonics are significantly different. Comparisons of the υn measurements with theoretical calculations are also made.
|Original language||English (US)|
|State||Published - Nov 12 2019|
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