Non-linear flow modes of identified particles in Pb–Pb collisions at √sNN=5.02TeV with the ALICE detector

Abstract

The non-linear flow modes, v4,22, v5,32 and v6,33 as a function of transverse momentum (pT) have been measured for the first time in Pb–Pb collisions at for identified particles, i.e. charged pions, kaons and (anti-)protons. These observables probe the contribution of the second and third initial anisotropy coefficients to the higher order flow harmonics. Interestingly, all the characteristic features observed in previous pT-differential as well as pT-integrated measurements (e.g. v2 and v3) for various particle species are present in these measurements, i.e. increase of magnitude with increasing centrality percentile, a mass ordering in the low pT region and a particle type grouping in the intermediate pT region. The results cover 0–1% (ultra-central collisions), 10–20% (mid-central collisions) and 40–50% (mid-peripheral collisions) centrality intervals and allow to test models that attempt to describe initial conditions and the mode-coupling of different harmonics.