Measurements of anisotropic flow and flow fluctuations in Xe–Xe and Pb–Pb collisions with ALICE

Abstract

Anisotropic flow is a key observable to characterise the system created in heavy-ion collisions, as it is sensitive to the system’s initial state, transport properties, the equation of state and freeze-out conditions. In these proceedings we present the anisotropic flow coefficients of inclusive charged particles in Pb–Pb collisions at √sNN = 2.76 and 5.02 TeV, and in Xe–Xe collisions at √sNN = 5.44 TeV. The results are reported for a wide range of particle transverse momentum within the pseudo-rapidity range |η| < 0.8 at different collision centralities. The energy and system dependence are found to place strong constraints on the temperature dependence of η/s and the modeling of the initial state, respectively. We also present detailed studies of flow fluctuations in heavy-ion collisions, in order to precisely characterise the underlying flow probability density function. We find evidence of non-Bessel-Gaussian fluctuations and discuss the origin of this observation.