Flow and transverse momentum correlations in Pb+Pb and Xe+Xe collisions with ATLAS

Correlation of mean transverse momentum ($[p_T]$) of particles with the n-th order anisotropic flow harmonics ($v_n$) in heavy ion collisions is sensitive to the initial-state conditions. Measurement of a modified Pearson’s Correlation Coefficient between $v_n$ and $[p_T]$ with the ATLAS detector are presented using 22~${\mathalpha{\mu}}\textrm{b}^{-1}$ of $\sqrt{s_{\mathrm{NN}}}=5.02$~$\TeV$ TeV Pb+Pb collisions for harmonics n=2, 3 and 4. The results are shown as a function of event centrality quantified as the number of charged particles ($N_{ch}$) or the number of nucleon participants. The correlation coefficient depends strongly on centrality and also on the choice of transverse momentum range of the particles for all harmonics. Similar ATLAS analysis is in process for 3~${\mathalpha{\mu}}\textrm{b}^{-1}$ of $\sqrt{s_{\mathrm{NN}}}=5.44$~$\TeV$ Xe+Xe collisions. Comparison between Pb+Pb and Xe+Xe collisions can shed light on the system-size dependence of this correlation and the impact of deformation. The measurement will provide inputs for better understanding of the dynamics of heavy ion collisions and can help constrain theoretical models.