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

Abstract

The elliptic (v₂), triangular (v₃), and quadrangular (v₄) flow coefficients of π^±, K^±, p+p¯,Λ+Λ¯,KS0\[ \mathrm{p}+\overline{\mathrm{p}},\kern0.5em \Lambda +\overline{\Lambda},\kern0.5em {\mathrm{K}}_{\mathrm{S}}^0 \], and the ϕ-meson are measured in Pb-Pb collisions at sNN=5.02\[ {\sqrt{s}}_{\mathrm{NN}}=5.02 \] 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+p¯\[ \mathrm{p}+\overline{\mathrm{p}} \]. 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 v₂, which tests both particle mass dependence and type scaling, follows p+p¯\[ \mathrm{p}+\overline{\mathrm{p}} \]v₂ at low p_T and π^±v₂ 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+p¯\[ \mathrm{p}+\overline{\mathrm{p}} \] 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 sNN=2.76\[ \sqrt{s_{\mathrm{NN}}}=2.76 \] TeV is also provided.