Measurement of exclusive γγ→ℓ + ℓ − production in proton–proton collisions at √s=7 TeV with the ATLAS detector
This Letter reports a measurement of the exclusive γγ→ℓ + ℓ − (ℓ=e, μ) 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 crit...
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| Formato: | JOUR |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_03702693_v749_n_p242_Aad |
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| Sumario: | This Letter reports a measurement of the exclusive γγ→ℓ + ℓ − (ℓ=e, μ) 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 σ γγ→e + e − excl. =0.428 ± 0.035 (stat.) ± 0.018 (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 T >12 GeV and pseudorapidity |η|<2.4. For muon pairs with invariant mass greater than 20 GeV, muon transverse momentum p T >10 GeV and pseudorapidity |η|<2.4, the cross-section is determined to be σ γγ→μ + μ − excl. =0.628 ± 0.032 (stat.) ± 0.021 (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. © 2015 CERN for the benefit of the ATLAS Collaboration. |
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