Measurement of exclusive γγ →W⁺W^- production and search for exclusive Higgs boson production in pp collisions at √s = 8 TeV using the ATLAS detector

Abstract

Searches for exclusively produced W boson pairs in the process pp(γγ)→pW⁺W^-p and an exclusively produced Higgs boson in the process pp(gg)→pHp have been performed using e^±μ^∓ final states. These measurements use 20.2 fb^-1 of pp collisions collected by the ATLAS experiment at a center-of-mass energy √s = 8 TeV at the LHC. Exclusive production of W⁺W^- consistent with the Standard Model prediction is found with 3.0σ significance. The exclusive W+W- production cross section is determined to be σ(γγ→W⁺W^-→e^±μ^∓X) = 6.9 ± 2.2(stat) ± 1.4(sys) fb, in agreement with the Standard Model prediction. Limits on anomalous quartic gauge couplings are set at 95% confidence level as -1.7×10^-6<a^W₀/Λ²<1.7×10^-6 GeV^-2 and -6.4×10^-6<a^W_C/Λ²<6.3×10^-6 GeV^-2. A 95% confidence-level upper limit on the total production cross section for an exclusive Higgs boson is set to 1.2 pb.