Collective behavior in heavy-ion collisions

Abstract

Nuclear collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) occur at energies that enable the creation of a new state of matter, called the quark-gluon plasma, with an energy density similar to that achieved in the early universe shortly after the Big Bang. The medium generated in such collisions exhibits collective behavior characteristic of a strongly coupled, near-inviscid fluid, which undergoes a rapid three-dimensional expansion. I will present a review of the most striking observations made with heavy ion collisions at RHIC and LHC. The new data from RHIC and the LHC explore the evolution of the quark-gluon plasma state over two orders of magnitude in collision energy, allowing significant tests of phenomenological models that have successfully described earlier data.