Anisotropic flow of identified particles in Pb-Pb collisions at ${\sqrt{s}}_{NN}=5.02$ TeV

The elliptic (v 2), triangular (v 3), and quadrangular (v 4) flow coefficients of π±, K±, $p+\overline{p},\phantom{\rule{0.5em}{0ex}}\Lambda +\overline{\Lambda },\phantom{\rule{0.5em}{0ex}}{K}_{S}^{0}$ , and the ϕ-meson are measured in Pb-Pb collisions at ${\sqrt{s}}_{NN}=5.02$ TeV. Results obtained with the scalar product method are reported for the rapidity range |y| < 0.5 as a function of transverse momentum, p T, at different collision centrality intervals between 0–70%, including ultra-central (0–1%) collisions for π ±, K±, and $p+\overline{p}$ . For p T < 3 GeV/c, the flow coefficients exhibit a particle mass dependence. At intermediate transverse momenta (3 < p T < 8–10 GeV/c), particles show an approximate grouping according to their type (i.e., mesons and baryons). The ϕ-meson v 2, which tests both particle mass dependence and type scaling, follows $p+\overline{p}$ v 2 at low p T and π± v 2 at intermediate p T. The evolution of the shape of v n(p T) as a function of centrality and harmonic number n is studied for the various particle species. Flow coefficients of π ±, K±, and $p+\overline{p}$ for p T < 3 GeV/c are compared to iEBE-VISHNU and MUSIC hydrodynamical calculations coupled to a hadronic cascade model (UrQMD). The iEBE-VISHNU calculations describe the results fairly well for p T < 2.5 GeV/c, while MUSIC calculations reproduce the measurements for p T < 1 GeV/c. A comparison to v n coefficients measured in Pb-Pb collisions at $\sqrt{{s}_{NN}}=2.76$ TeV is also provided.