Anisotropic flow of identified hadrons in Xe-Xe collisions at $\sqrt{s_{\rm NN}}$ = 5.44TeV

The collaboration
CERN-EP-2021-149, 2021.

Abstract (data abstract)
Measurements of elliptic ($v_2$) and triangular ($v_3$) flow coefficients of $\pi^{\pm}$, $\rm{K}^{\pm}$, p+$\rm\overline{p}$, ${\rm K}^{0}_{\rm{S}}$, and $\Lambda$+$\overline{\Lambda}$ obtained with the scalar product method in Xe-Xe collisions at $\sqrt{s_{\rm{NN}}} = 5.44$ TeV are presented. The results are obtained in the rapidity range $\left | y \right |<0.5$ and reported as a function of transverse momentum, $p_{\rm T}$, for several collision centrality classes. The flow coefficients exhibit a particle mass dependence for $p_{\rm T}<3$ GeV/c, while a grouping according to particle type (i.e., meson and baryon) is found at intermediate transverse momenta ($3<p_{\rm T}<8$ GeV/c). The magnitude of the baryon $v_{2}$ is larger than that of mesons up to $p_{\rm T}=6$ GeV/c. The centrality dependence of the shape evolution of the $p_{\rm T}$-differential $v_2$ is studied for the various hadron species. The $v_2$ coefficients of $\pi^{\pm}$, $\rm{K}^{\pm}$, and p+$\rm\overline{p}$ are reproduced by MUSIC hydrodynamic calculations coupled to a hadronic cascade model (UrQMD) for $p_{\rm T}<1$ GeV/c. A comparison with $v_{\rm n}$ measurements in the corresponding centrality intervals in Pb--Pb collisions at $\sqrt{s_{\rm{NN}}} = 5.02$ TeV yields an enhanced $v_2$ in central collisions and diminished value in semicentral collisions.