Early hydrodynamisation, energy loss and small systems in holographic heavy ion collisions

Abstract

There has been much recent progress in describing heavy ion collisions using strongly coupled methods. We start by introducing a few caveats in applying holography to QCD, after which we will highlight recent progress on the initial stage, by simulating shock collisions in the dual gravitational theory. Secondly, we describe an attempt at describing jet evolution through strongly coupled plasma, where we specifically also included the width of the jet, and the interplay of this width with the energy lost as the jet propagates through the plasma. Lastly, there has been much recent discussion about the formation of quark-gluon plasma in small systems at low multiplicies, such as produced in proton-nucleus or even proton-proton collisions. At infinitely strong coupling it is possible to estimate that this may be possible, provided that the particle multiplicity satisfies dN[subscript tot] /dy ≥ 4.