Measurement of exclusive gamma gamma -> l(+)l(-) production in proton-proton collisions at root s=7 TeV with the ATLAS detector



Aad, G, Collaboration, Atlas, Abdallah, J, Abdinov, O, Aben, R, Abolins, M, AbouZeid, OS, Abramowicz, H, Abreu, H, Abreu, R
et al (show 2840 more authors) (2015) Measurement of exclusive gamma gamma -> l(+)l(-) production in proton-proton collisions at root s=7 TeV with the ATLAS detector. PHYSICS LETTERS B, 749. pp. 242-261.

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Abstract

This Letter reports a measurement of the exclusive $\gamma\gamma\rightarrow \ell^+\ell^- (\ell=e, \mu)$ cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV by the ATLAS experiment at the LHC, based on an integrated luminosity of $4.6$ fb$^{-1}$. For the electron or muon pairs satisfying exclusive selection criteria, a fit to the dilepton acoplanarity distribution is used to extract the fiducial cross-sections. The cross-section in the electron channel is determined to be $\sigma_{\gamma\gamma\rightarrow e^+e^-}^{\mathrm{excl.}} = 0.428 \pm 0.035 (\mathrm{stat.}) \pm 0.018 (\mathrm{syst.})$ pb for a phase-space region with invariant mass of the electron pairs greater than 24 GeV, in which both electrons have transverse momentum $p_\mathrm{T}>12$ GeV and pseudorapidity $|\eta|<2.4$. For muon pairs with invariant mass greater than 20 GeV, muon transverse momentum $p_\mathrm{T}>10$ GeV and pseudorapidity $|\eta|<2.4$, the cross-section is determined to be $\sigma_{\gamma\gamma\rightarrow \mu^+\mu^- }^{\mathrm{excl.}} = 0.628 \pm 0.032 (\mathrm{stat.}) \pm 0.021 (\mathrm{syst.})$ pb. When proton absorptive effects due to the finite size of the proton are taken into account in the theory calculation, the measured cross-sections are found to be consistent with the theory prediction.

Item Type: Article
Additional Information: 12 pages + references + author list + cover pages (34 pages total), 4 figures, 3 tables, submitted to Phys. Lett. B, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2014-13/
Uncontrolled Keywords: hep-ex, hep-ex
Depositing User: Symplectic Admin
Date Deposited: 24 Nov 2017 08:30
Last Modified: 19 Jan 2023 06:49
DOI: 10.1016/j.physletb.2015.07.069
Open Access URL: http://eprints.lancs.ac.uk/68134/1/art_3A10.1007_2...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3012794