First Results with Heavy-Ion Collisions at LHC from ALICE

TL;DR

This paper reports initial findings from the ALICE experiment at CERN on Pb-Pb collisions at 2.76 TeV, revealing properties of the hot, dense matter created and its dependence on collision centrality.

Contribution

It provides the first characterization of quark-gluon plasma properties at LHC energies, including multiplicity, flow, and particle production measurements.

Findings

Charged-particle multiplicity increases with centrality.

Elliptic flow observed, indicating collective behavior.

Strange particle production and high-momentum suppression measured.

Abstract

In November 2010 the ALICE experiment at CERN has collected the first Pb--Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV produced by the LHC. A first characterization of the hot and dense state of matter produced in this new energy domain became available shortly after the run. In this paper we present the results on charged-particle multiplicity, Bose-Einstein correlations, elliptic flow and their dependence on the collision centrality. Results from first measurements of strange and identified particle production and suppression of high-momentum hadrons with respect to $pp$ collisions are also reported.