Quartic gauge couplings and the radiation zero in pp→l±νγγ events at the LHC

We report a study of the process pp→l±νγγ at CERN's Large Hadron Collider, using a leading order partonic-level event generator interfaced to the Pythia program for showering and hadronisation and a with a generic detector simulation. The process is sensitive to possible anomalous quartic gauge boson couplings of the form WWγγ. It is shown how unitarity-safe limits may be placed on these anomalous couplings by applying a binned maximum likelihood fit to the distribution of the two-photon invariant mass, Mγγ, below a cutoff of ∝1 TeV. Assuming 30 fb-1 of integrated luminosity, the expected limits are two orders of magnitude tighter than those available from LEP. It is also demonstrated how the Standard Model radiation zero feature of the q anti q'→Wγγ process may be observed in the difference between the two-photon and charged lepton pseudo-rapidities. (orig.)