Heavy-flavour decay lepton measurements in pp, p–Pb, and Pb–Pb collisions with ALICE at the LHC

Sarah Lapointe

doi:10.1016/j.nuclphysa.2014.02.015

Abstract

We present the measurements of electrons and muons from the semi-leptonic decays of heavy-flavour hadrons measured in the central and forward rapidity regions with ALICE in pp ( s = 2.76 TeV and 7 TeV), Pb–Pb ( s NN = 2.76 TeV ), and p–Pb ( s NN = 5.02 TeV ) collisions at the LHC. The p T -differential production cross section in pp collisions, the elliptic flow in Pb–Pb collisions, and the nuclear modification factor in Pb–Pb and p–Pb collisions are shown. The results are compared to theoretical predictions.

Highlights

The overall objective of ALICE is to study the QCD matter that forms from the collisions of Pb ions in the CERN LHC [1]
I.e. charm and beauty, are considered to be excellent probes of such matter as they are predominantly produced via hard parton scatterings, in the initial phase of the collision
An experimental observable sensitive to the energy loss is the nuclear modification factor (RAA), which is the ratio of particle yields in heavy-ion collisions to those in pp collisions, scaled by the number of binary collisions

Summary

Introduction

The overall objective of ALICE is to study the QCD matter that forms from the collisions of Pb ions in the CERN LHC [1]. I.e. charm and beauty, are considered to be excellent probes of such matter as they are predominantly produced via hard parton scatterings, in the initial phase of the collision. They are expected to lose energy through elastic scattering and radiative processes. It is expected to be equal to unity in the absence of initial and final state medium effects Another experimental observable of interest is the elliptic flow (ν2), which is the azimuthal anisotropy in momentum space that arises from an “almond” shaped overlap region of a non-central heavy-ion collision expanding under anisotropic pressure gradients. The measured pT-differential production cross sections, nuclear modification factor, and elliptic flow are shown and compared to the respective theoretical predictions

Heavy-flavour measurements with electrons and muons in ALICE

Measurements in pp collisions

Measurements in Pb–Pb collisions

Measurements in p–Pb collisions

Conclusions