Measurement of exclusive production in proton–proton collisions at with the ATLAS detector》.pdfVIP

Physics Letters B 749 (2015) 242–261 Contents lists available at ScienceDirect Physics Letters B /locate/physletb Measurement of exclusive γ γ → +− production in proton–proton collisions at √s = 7 TeV with the ATLAS detector .ATLAS Collaboration a r t i c l e i n f o a b s t r a c t Article history: This Letter reports a measurement of the exclusive γ γ → +− ( = e , μ) cross-section in proton–proton Received 23 June 2015 collisions at a centre-of-mass energy of 7 TeV by the ATLAS experiment at the LHC, based on an inte- Received in revised form 27 July 2015 grated luminosity of 4.6 fb−1. For the electron or muon pairs satisfying exclusive selection criteria, a fit Accepted 28 July 2015 to the dilepton acoplanarity distribution is used to extract the fiducial cross-sections. The cross-section Available online 31 July 2015 excl. in the electron channel is determined to be σ + − = 0.428 ± 0.035 (stat.) ± 0.018 (syst.) pb Editor: W.-D. Schlatter γ γ →e e for a phase–space region with invariant mass of the electron pairs greater than 24 GeV, in which