ALICE Highlights

Francesco Collaboration

doi:10.3390/proceedings2019013006

Abstract

Deconfined strongly interacting QCD matter is produced in the laboratory at the highest energy densities in heavy-ion collisions at the LHC. A selection of recent results from ALICE is presented, spanning observables from the soft sector (bulk particle production and correlations), the hard probes (charmed hadrons and jets) and signatures of possible collective effects in pp and p–Pb collisions with high multiplicity. Finally, the perspectives after the detectors upgrades, taking place in the period 2019–2020, are presented.

Highlights

Heavy-ion collisions realize the ideal conditions to recreate in laboratory a QCD-deconfined medium with a high energy density and temperature
Central barrel system is placed at midrapidity in a solenoidal magnetic field of B = 0.5 T, while the forward region is covered by specific detectors, in particular with a large muon detector up to pseudorapidity η ≈ 4
Since the magnitude of the impact parameter is between zero and the sum of the radii of two colliding nuclei, i.e., at the level of few fm, it cannot be directly measured, and centralities are usually classified using the multiplicity of charged particles, the transverse energy at midrapidity, or the energy measured in the forward rapidity region

Summary

Introduction

Heavy-ion collisions realize the ideal conditions to recreate in laboratory a QCD-deconfined medium with a high energy density and temperature. Two colliding nuclei, extended object, interact whenever the distance of their centers in the transverse plane is larger than zero. Such a distance, which is different event-by-event, is the so-called impact parameter. Since the magnitude of the impact parameter is between zero and the sum of the radii of two colliding nuclei, i.e., at the level of few fm, it cannot be directly measured, and centralities are usually classified using the multiplicity of charged particles, the transverse energy at midrapidity, or the energy measured in the forward rapidity region. The Glauber model allows associating to each centrality class the number of participating nucleons (Npart ) and the number of binary nucleon–nucleon collisions (Ncoll ), which are fundamental quantities to characterize the strength of the interaction

Soft Probes

The Size of the Medium

Anisotropic Flow

Hard Probes

Charmed Probes