Light flavour hadron production in the ALICE experiment at LHC

Angela Badalà,V Greco,M La Cognata,F Rizzo,C Spitaleri,S Pirrone

doi:10.1051/epjconf/201611703006

Abstract

Unique among the LHC experiments, ALICE has excellent particle identification capabilities for the measurement of light-flavour hadrons. A large number of hadron species from pions to multi-strange baryons and light nuclei have been measured over a large transverse momentum region. The measurement of the production of these particles is a valuable tool to study the properties of the medium formed in heavy-ion collisions. In particular they give information on the collective phenomena of the fireball, on the parton energy loss in the hot QCD medium and on the hadronization mechanisms such as recombination and statistical hadronization. The measurements in pp and in p-nucleus collisions provide the necessary baseline for heavy-ion data and help to investigate the effects of the ordinary nuclear matter. In this paper some of the main ALICE results on identified light-flavour hadron production in Pb–Pb collisions at √s NN = 2.76 TeV and p–Pb collisions at √s NN = 5.02 TeV will be presented.

Highlights

Heavy-ion collisions at ultra-relativistic energies allow one to study the physics of strongly interacting matter and to characterize the Quark-Gluon Plasma (QGP), a state of deconfined quarks and gluons
In p–Pb collisions these ratios increase with multiplicity, with Ξ/π reaching the saturation level observed in central Pb–Pb collisions and Ω/π being compatible with the value for peripheral Pb–Pb collisions
The ALICE experiment has performed a comprehensive study of the light flavour hadrons and light nuclei, in a wide range of pT for events collected in pp, p–Pb and Pb–Pb collisions during the first LHC run phase

Summary

Introduction

Heavy-ion collisions at ultra-relativistic energies allow one to study the physics of strongly interacting matter and to characterize the Quark-Gluon Plasma (QGP), a state of deconfined quarks and gluons. In high-energy interactions hadrons are expected to be produced in approximate chemical and thermal equilibrium. The production of particles formed only by light quarks (u, d, s) is an important tool for the understanding of particle production mechanisms in high energy collisions and to study the collective phenomena characterizing the dynamical evolution of the fireball. The study of particles with strangeness helps in understanding of the hadrochemistry of the matter created in the collisions since no net strangeness is present in the colliding nuclei. High energy heavy-ion collisions offer the opportunity to study light (anti-)nuclei (such as d, 3He, 4He) and hypernuclei (such as 3ΛH) and to test their production mechanisms.

Particle identification in ALICE and selected results

Summary and conclusions