Abstract
This paper describes the measurements of flow harmonics π£2βπ£6 in 3β’πβ’bβ1 of Xe+Xe collisions at βπ πβ’π=5.44 TeV performed using the ATLAS detector at the Large Hadron Collider (LHC). Measurements of the centrality, multiplicity, and πT dependence of the π£π 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 nonflow correlations in small collision systems. This nonflow removal is shown to have a significant influence on the measured π£π at high πT, especially in peripheral events. Comparisons of the measured π£π with measurements in Pb+Pb collisions and π+Pb collisions at βπ πβ’π=5.02 TeV are also presented. The π£π values in Xe+Xe collisions are observed to be larger than those in Pb+Pb collisions for π=2, 3, and 4 in the most central events. However, with decreasing centrality or increasing harmonic order π, the π£π values in Xe+Xe collisions become smaller than those in Pb+Pb collisions. The π£π in Xe+Xe and Pb+Pb collisions are also compared as a function of the mean number of participating nucleons, β¨πpartβ©, and the measured charged-particle multiplicity in the detector. The π£3 values in Xe+Xe and Pb+Pb collisions are observed to be similar at the same β¨πpartβ© or multiplicity, but the other harmonics are significantly different. The ratios of the measured π£π in Xe+Xe and Pb+Pb collisions, as a function of centrality, are also compared to theoretical calculations.