Elliptic flow of electrons from beauty-hadron decays extracted from Pb\u2013Pb collision data at sqrt{s_mathrm{NN}} = 2.76 hbox {TeV}

D Moreira De Godoy,C Klein-Bösing,F Herrmann,M Klasen,A A P Suaide

doi:10.1140/epjc/s10052-018-5843-8

Abstract

We present a calculation of the elliptic flow of electrons from beauty-hadron decays in semi-central Pb–Pb collisions at centre-of-mass energy per colliding nucleon pair, represented as sqrt{s_mathrm{NN}}, of 2.76 TeV. The result is obtained by the subtraction of the charm-quark contribution in the elliptic flow of electrons from heavy-flavour hadron decays in semi-central Pb–Pb collisions at sqrt{s_mathrm{NN}} = 2.76 hbox {TeV} recently made publicly available by the ALICE collaboration.

Highlights

RAA =dNAA/d pT dσpp/d pT (1)where dNAA/d pT is the transverse momentum differential yield in nucleus-nucleus (AA) collisions; TAA is the average nuclear overlap function in nucleus-nucleus collisions, given by the ratio of the average number of binary collisions and the inelastic cross section; and dσpp/d pT is the pT-differential cross section in proton-proton collisions
We present a calculation of the elliptic flow of electrons from beauty-hadron decays in semi-central Pb– Pb collisions at cent√re-of-mass energy per colliding nucleon pair, represented as sNN, of 2.76 TeV
We present a method to subtract the contribution of charm quarks in the published measurement of the elliptic flow of ePlbe–cPtrboncsoflrliosmionhseaavty√-flsaNvNou=r ha2d.7ro6nTdeeVcaypserifnorsmemedi-cbeynttrhael ALICE collaboration

Summary

Introduction

RAA =dNAA/d pT dσpp/d pT (1)where dNAA/d pT is the transverse momentum ( pT) differential yield in nucleus-nucleus (AA) collisions; TAA is the average nuclear overlap function in nucleus-nucleus collisions, given by the ratio of the average number of binary collisions and the inelastic cross section; and dσpp/d pT is the pT-differential cross section in proton-proton (pp) collisions. A suppression of the yield of D mesons and leptons from heavy-flavour hadron decays (RAA < 1) for pT > lisions 3 at. [15,16,17,18] and in lead-lead (Pb–Pb) collisions and 5.02 TeV at the Large Hadron Collider (LHC) [19,20,21,22,23,24,25], indicating energy loss of heavy flavours in the medium. An experimental hint to the quark mass dependence of the heavy-flavour energy loss has been found in the comparison of the RAA of D mesons and non-prompt. The observed difference of these measurements is described by model calculations [28,29] as predominantly due to the quark mass dependence of the parton energy loss. The interaction of heavy quarks with the medium can be further investigated with the azimuthal anisotropy of heavyflavour particles, extracted from the coefficients vn of the Fourier decomposition of the particle azimuthal distribution in the transverse plane [30] dN d (φ − Ψn) ∝

Methods

Results

Conclusion