Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: Exclusive dimuon production in ultraperipheral Pb plus Pb collisions at √SNN=5.02 TeV with ATLAS
Other Titles: Exclusive dimuon production in ultraperipheral Pb plus Pb collisions at root SNN=5.02 TeV with ATLAS
Author: Aad, G.
Abbott, B.
Abbott, D.C.
Abud, A.A.
Abeling, K.
Abhayasinghe, D.K.
Abidi, S.H.
AbouZeid, O.S.
Abraham, N.L.
Abramowicz, H.
Abreu, H.
Abulaiti, Y.
Acharya, B.S.
Achkar, B.
Adam, L.
Bourdarios, C.A.
Adamczyk, L.
Adamek, L.
Adelman, J.
Adersberger, M.
et al.
Citation: Physical Review C, 2021; 104(2):1-32
Publisher: American Physical Society
Issue Date: 2021
ISSN: 2469-9993
Statement of
G. Aad, B. Abbott, D. C. Abbott, A. Abed Abud, K. Abeling, D. K. Abhayasinghe
Abstract: Exclusive dimuon production in ultraperipheral collisions (UPC), resulting from photon-photon interactions in the strong electromagnetic fields of colliding high-energy lead nuclei, PbPb(γγ)→μ+μ−(Pb(★)Pb(★)), is studied using Lint=0.48nb−1 of √sNN=5.02TeV lead-lead collision data at the LHC with the ATLAS detector. Dimuon pairs are measured in the fiducial region pT,μ>4 GeV, ∣∣ημ|<2.4, invariant mass mμμ>10 GeV, and pT,μμ<2 GeV. The primary background from single-dissociative processes is extracted from the data using a template fitting technique. Differential cross sections are presented as a function of mμμ, absolute pair rapidity (∣∣yμμ∣∣), scattering angle in the dimuon rest frame (|cosϑ★μμ∣∣), and the colliding photon energies. The total cross section of the UPC γγ→μ+μ− process in the fiducial volume is measured to be σμμfid=34.1±0.3(stat.)±0.7(syst.) μb. Generally good agreement is found with calculations from STARlight, which incorporate the leading-order Breit-Wheeler process with no final-state effects, albeit differences between the measurements and theoretical expectations are observed. In particular, the measured cross sections at larger ∣∣yμμ∣∣ are found to be about 10–20% larger in data than in the calculations, suggesting the presence of larger fluxes of photons in the initial state. Modification of the dimuon cross sections in the presence of forward and/or backward neutron production is also studied and is found to be associated with a harder incoming photon spectrum, consistent with expectations.
Rights: © 2021 CERN, for the ATLAS Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
DOI: 10.1103/PhysRevC.104.024906
Published version:
Appears in Collections:Physics publications

Files in This Item:
File Description SizeFormat 
hdl_132522.pdfPublished version2.1 MBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.