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 < aW0/Λ²<1.7×10⁻⁶ GeV⁻² and −6.4×10⁻⁶ < aWC/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.