Measurements of elliptic ($v_2$) and triangular ($v_3$) flow coefficients of $\pi^{ \pm}$, K$^{ \pm}$, p+$\rm \overline{ p}$, 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 $\pi^{ \pm}$, 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.
Categories: nucl-ex hep-ex