Measurement of open heavy-flavour production as a function of charged-particle multiplicity with ALICE at the LHC

Sibaliso Mhlanga

doi:10.1088/1742-6596/889/1/012018

Abstract

Heavy quarks are produced in the early stages of ultra-relativistic hadron collisions via hard scatterings and are an important tool for studying different aspects of Quantum Chromodynamics (QCD) in hadronic collisions. Charged-particle multiplicity gives information on the global characteristics of the event and could be used to characterize particle production mechanisms. In hadronic collisions at Large Hadron Collider (LHC) energies, there is a significant contribution of multi-parton interactions. The measurement of heavy-flavour yields as a function of charged-particle multiplicity gives insight into the mechanisms influencing their production in hadronic collisions at these energies and it is a tool to test the possible influence of multi-parton interactions. Furthermore, the charged-particle multiplicity dependence of open heavy flavours is used to test the ability of QCD theoretical models to describe the data. In ALICE, heavy-flavour production is measured via the hadronic and semi-leptonic decay channels (electrons at central rapidity and muons at forward rapidity). Charged-particle multiplicity is measured at central and forward rapidity. We will present the results on open heavy-flavour production as a function of the charged-particle multiplicity in pp and p–Pb collisions. Results will be compared to quarkonia measurements as well as theoretical model calculations.

Highlights

Heavy quarks are abundantly produced at the Large Hadron Collider (LHC) [1] in the early stages of hadronic collisions via hard scattering processes and experience the full evolution of the collision
The measurement of heavy flavours in pp collisions can be used to test pQCD calculations. They provide an essential baseline for the studies in nuclear (p–Pb and Pb–Pb) collisions. Their production in nuclear collisions is modified by cold nuclear matter effects (CNM) such as shadowing and energy loss [2, 3]
The knowledge of these effects is fundamental for understanding the interactions of heavy quarks with the deconfined medium formed in heavy-ion collisions where the modified transverse momentum distribution can be used to infer the medium’s characteristics

Summary

Introduction

Heavy quarks (charm and beauty) are abundantly produced at the LHC [1] in the early stages of hadronic collisions via hard scattering processes and experience the full evolution of the collision. The measurement of heavy flavours in pp collisions can be used to test pQCD calculations They provide an essential baseline for the studies in nuclear (p–Pb and Pb–Pb) collisions. The charged-particle multiplicity dependence of open heavy-flavour yields provides insight into mechanisms of particle production in hadronic collisions. Two arrays of scintillator detectors (V0A and V0C) placed on both sides of the interaction point provide centrality in Pb–Pb collisions as well as trigger information. The measurement of prompt and non-prompt (produced via the decay of beauty hadrons) J/ψ → e+e+ (BR = 5.97±0.03 %) and J/ψ → μ+μ+ (BR = 5.96±0.03 %) at central and forward rapidity are reported in [13]

Results

D-meson production in p–Pb collisions

Conclusion