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

Abstract

The non-linear flow modes, v(4,22), v(5,32) and v(6,33) as a function of transverse momentum (p(T)) have been measured for the first time in Pb-Pb collisions at root s(NN) = 5.02 TeV 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 p(T)-differential as well as p(T)-integrated measurements (e.g. v(2) and v(3)) for various particle species are present in these measurements, i.e. increase of magnitude with increasing centrality percentile, a mass ordering in the low p(T) region and a particle type grouping in the intermediate p(T) 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.