Collectivity in small and large collision systems at the LHC with ALICE

Abstract

Interactions of protons (pp) or of a proton with a lead nucleus (p–Pb) were not expected to form a deconfined hot and dense matter, called the Quark-Gluon Plasma (QGP), which is instead produced in heavy-ion collisions. However, high-multiplicity events in small collision systems exhibit signs of collectivity, which are understood as a signature of the QGP emergence in heavy-ion collisions. An excellent tool to probe the presence of collectivity is the anisotropic flow measured with two- and multi-particle cumulants. In these proceedings, we present the first measurement of flow coefficients and their magnitude correlations using symmetric cumulants for charged particles in pp collisions at centre-of-mass energies of , p–Pb at , Xe–Xe at and Pb–Pb collisions at , collected during the LHC Run 2 programme. In addition, the flow coefficients of identified particles in p–Pb collisions are shown. Such a broad spectrum of colliding systems with different energies and a wide range of multiplicity allows for a detailed investigation of their collision dynamics. Non-flow effects, which are azimuthal correlations not originating from a common symmetry plane, are suppressed with the pseudorapidity separation and the subtraction method. These results provide an important insight into the nature of collective phenomena in different collision systems.