Heavy Ions Overview
M. van Leeuwen
A short overview of selected results from heavy ion collisions at RHIC and LHC is presented. The results cover three key areas: collective effects in soft particle production in heavy ion collisions, evidence for similar effects in pp and p-Pb collisions, and hard probes of the Quark Gluon Plasma. The results are compared to theoretical models. The measurements of collective effects constrain both the initial entropy production and the viscosity of the Quark Gluon Plasma. The results from hard probes show that radiative parton energy loss plays an important role in these systems.