Flow harmonics in heavy-ion physics at ATLAS and CMS

This paper summarises recent measurements of flow harmonics from the ATLAS and CMS Collaborations. Measurements of the flow of heavy-flavour hadrons in Pb-Pb by CMS are discussed. The observed flow for $c$ hadrons are found to be similar to inclusive charged-particles flow. In contrast, the $b$ hadrons are found to exhibit weaker flow, and in particular the flow of $\Upsilon$ states is consistent with zero. The ATLAS experiment reported measurement of high-$p_\mathrm{T}$ jets flow in Pb-Pb collisions. Significant values of $v_2$ and $v_3$ are observed and follow the trend defined by the initial-collision geometry. The ATLAS experiment also measured flow in photo-nuclear collisions. A signal for $v_2$ and $v_3$ is found to resemble that in $p-p$ collisions however the magnitudes are slightly smaller. The measurement of the $v_n - p_\mathrm{T}$ correlation for Pb-Pb and Xe-Xe is also reported with relation to the nuclear geometry.