Exclusive W+W- production measured with the CMS experiment and constraints on Anomalous Quartic Gauge Couplings

A search for exclusive or quasi-exclusive W+W- production induced by photon-photon exchange in pp collisions at sqrt(s)=8 TeV is reported using data corresponding to an integrated luminosity of 19.7/fb. Events are selected by requiring the presence of an electron-muon pair with large transverse momentum pT gt 30 GeV and no associated charged particles detected from the same vertex. The observed yields and kinematic distributions are compatible with the Standard Model prediction for exclusive and quasi-exclusive W+W- production. The di-lepton transverse momentum spectrum is studied for deviations from the Standard Model, and the resulting upper limits are compared to predictions assuming anomalous quartic gauge couplings.