System-size dependence of the charged-particle pseudorapidity density at \(\sqrt {s_{NN}}\) = 5.02 TeV with ALICE

Abstract

We present the charged-particle pseudorapidity density in pp, p–Pb, and Pb–Pb collisions at sNN=5.02 TeV over a broad pseudorapidity range. The distributions are determined using the same experimental apparatus and methodologies, thereby minimizing systematic uncertainties, and providing clear and model-independent observations on the system-size dependence of the particle production at relativistic energies. An increase of particle production in Pb–Pb collisions near mid-rapidity, relative to pp collisions, is observed. The relative linearity in p–Pb collisions of the ratio to the smaller system indicate a coherent particle production throughout the longitudinal extend of the collision zone.