Effect of heavy-quark energy loss on the muon differential production cross section in Pb-Pb collisions at \sqrtsNN=5.5 TeV

TL;DR

This paper investigates how heavy-quark energy loss affects muon production in lead-lead collisions at LHC energies, focusing on nuclear modification factors and the role of different decay sources.

Contribution

It introduces a detailed analysis of heavy-quark energy loss effects on muon yields, incorporating nuclear shadowing and in-medium radiative energy loss models.

Findings

Heavy-quark energy loss significantly suppresses muon yields at high pt.

W and Z decay muons serve as a medium-blind reference for suppression.

Nuclear shadowing impacts parton distribution functions in the analysis.

Abstract

We study the nuclear modification factors RAA and RCP of the high transverse momentum 5<pt<60 GeV/c distribution of muons in Pb--Pb collisions at LHC energies. We consider two pseudo-rapidity ranges covered by the LHC experiments: $|\eta|<2.5$ and $2.5<\eta<4$. Muons from semi-leptonic decays of heavy quarks (c and b) and from leptonic decays of weak gauge bosons (W and Z) are the main contributions to the muon pt distribution above a few GeV/c. We compute the heavy quark contributions using available pQCD-based programs. We include the nuclear shadowing modification of the parton distribution functions and the in-medium radiative energy loss for heavy quarks, using the mass-dependent BDMPS quenching weights. Muons from W and Z leptonic decays, that dominate the yield at high pt, can be used as a medium-blind reference to observe the medium-induced suppression of beauty quarks.