Recent results on anisotropic flow and related phenomena in ALICE

TL;DR

Recent ALICE results from Run 2 at the LHC reveal new insights into the anisotropic flow of the Quark-Gluon Plasma at record energies, highlighting potential universality and the need for further analysis of correlation techniques.

Contribution

First observation of anisotropic flow in lead-lead collisions at 5.02 TeV, advancing understanding of matter properties in ultrarelativistic nuclear collisions.

Findings

Observation of anisotropic flow at 5.02 TeV

Potential universality of flow results across collision systems

Implication that physical conclusions may depend on subleading correlation orders

Abstract

The exploration of properties of an extreme state of matter, the Quark--Gluon Plasma, has broken new ground with the recent Run 2 operation of the Large Hadron Collider with heavy-ion collisions at the highest energy to date. With the heavy-ion data taken at the end of 2015, the ALICE Collaboration has made the first observation of anisotropic flow of charged particles and related phenomena in lead--lead collisions at the record breaking energy of 5.02 TeV per nucleon pair. The Run 2 results come after the proton-lead collisions, which provided a lot of unexpected results obtained with two- and multi-particle correlation techniques. In these proceedings, a brief overview of these results will be shown. We will discuss how they further enlighten the properties of matter produced in ultrarelativistic nuclear collisions. We indicate the possibility that, to leading order, the striking universality of flow results obtained with correlation techniques in pp, p--A and A--A collisions might have purely mathematical origin, and that physical conclusions therefore could be drawn only from the subleading orders.