Shrinking the Quark Gluon Plasma

TL;DR

This paper predicts how flow observables in small and large collision systems at the LHC depend on system size, aiming to clarify whether Quark Gluon Plasma can form in very small droplets.

Contribution

It provides theoretical predictions for ArAr and OO collision experiments at the LHC, analyzing system size effects on flow observables to distinguish QGP formation scenarios.

Findings

Linear response dominates in smaller systems.

Linear+cubic response accurately predicts multi-particle cumulants in large systems.

System size influences the response mechanism of the Quark Gluon Plasma.

Abstract

In recent years the understanding on the limits of the smallest possible droplet of the Quark Gluon Plasma has been called into question. Experimental results from both the Large Hadron Collider and the Relativistic Heavy Ion Collider have provided hints that the Quark Gluon Plasma may be produced in systems as small as that formed in pPb or dAu collisions. Yet alternative explanations still exist from correlations arising from quarks and gluons in a color glass condensate picture. In order to resolve these two scenarios, a system size scan has been proposed at the Large Hadron Collider for collisions of ArAr and OO. Here we make predictions for a possible future run of ArAr and OO collisions at the Large Hadron Collider and study the system size dependence of a variety of flow observables. We find that linear response (from the initial conditions to the final flow harmonics) becomes more dominant in smaller systems whereas linear+cubic response can accurately predict multi-particle cumulants for a wide range of centralities in large systems.