$Z$ boson production in Pb+Pb collisions at $\sqrt{s_{\text{NN}}}$= 5.02 TeV measured by the ATLAS experiment

Abstract

The production yield of $Z$ bosons is measured in the electron and muon decay channels in Pb+Pb collisions at $\sqrt{s_{\text{NN}}}$ = 5.02 TeV with the ATLAS detector. Data from the 2015 LHC run corresponding to an integrated luminosity of 0.49 ${\text{nb}}^{-1}$ are used for the analysis. The $Z$ boson yield, normalised by the total total number of minimum-bias events and the mean nuclear thickness function, is measured as a function of dilepton rapidity and event centrality. The measurements in Pb+Pb collisions are compared with similar measurements made in proton$-$proton collisions at the same centre-of-mass energy. The nuclear modification factor is found to be consistent with unity for all centrality intervals. The results are compared with theoretical predictions obtained at next-to-leading order using nucleon and nuclear parton distribution functions. The normalised $Z$ boson yields in Pb+Pb collisions lie 1$-3$$\sigma$ above the predictions. The nuclear modification factor measured as a function of rapidity agrees with unity and is consistent with a next-to-leading-order QCD calculation including the isospin effect.

38 pages in total, author list starting page 22, 7 figures, 1 table, submitted to Physics Letters B. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2018-10/

References in corpus (13)

• PYTHIA 6.4 Physics and Manual
• Big-Bang Nucleosynthesis
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• New parton distributions for collider physics
• Glauber Modeling in High Energy Nuclear Collisions
• An NNLO subtraction formalism in hadron collisions and its application to Higgs boson production at the LHC
• Vector boson production at hadron colliders: a fully exclusive QCD calculation at NNLO
• NLO vector-boson production matched with shower in POWHEG
• Measurement of the $Z/{\gamma }^{\ast }$ boson transverse momentum distribution in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the ATLAS detector
• Measurement of the production and lepton charge asymmetry of $\text{W}$ bosons in Pb+Pb collisions at $\sqrt{s_{\mathbf{NN}}}=$ 2.76 TeV with the ATLAS detector
• Study of Z production in PbPb and pp collisions at sqrt(s[NN]) = 2.76 TeV in the dimuon and dielectron decay channels
• Observation of $Z$ production in proton-lead collisions at LHCb
• Coherent photon-photon interactions in very peripheral relativistic heavy ion collisions

Cited by in corpus (19)

• The ALICE experiment: a journey through QCD
• Progress in the Glauber model at collider energies
• Imaging the initial condition of heavy-ion collisions and nuclear structure across the nuclide chart
• Exclusive dimuon production in ultraperipheral Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with ATLAS
• Correlations between flow and transverse momentum in Xe+Xe and Pb+Pb collisions at the LHC with the ATLAS detector: a probe of the heavy-ion initial state and nuclear deformation
• NNLO nuclear parton distribution functions with electroweak-boson production data from the LHC
• Medium-induced modification of $Z$-tagged charged particle yields in Pb+Pb collisions at 5.02 TeV with the ATLAS detector
• Strong constraints on jet quenching in centrality-dependent $p$+Pb collisions at 5.02 TeV from ATLAS
• Constraints on the initial state of PbPb collisions via measurements of Z boson yields and azimuthal anisotropy at $\sqrt{s_{\mathrm{NN}}}=$ 5.02 TeV
• Shadowing in inelastic nucleon-nucleon cross section?
• Z-boson production in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=8.16$ TeV and Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Disentangling centrality bias and final-state effects in the production of high-$p_T$ ${\pi }^0$ using direct $\gamma$ in $d$$+$Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV
• Centrality dependence of electroweak boson production in PbPb collisions at the LHC
• Observation of top-quark pair production in lead-lead collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with the ATLAS detector
• Flavor and path-length dependence of jet quenching from inclusive jet and γ-jet suppression
• Measurement of the nuclear modification factor for muons from charm and bottom hadrons in Pb+Pb collisions at 5.02 TeV with the ATLAS detector
• Impact of scale, nuclear PDF and temperature variations on the interpretation of medium-modified jet production data from the LHC
• Measurement of the inclusive isolated-photon production cross section in pp and Pb$-$Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Geometric Bias and Centrality Dependence of Jet Quenching in High-Energy Nuclear Collisions