Study of the W+W−γ process and limits on anomalous quartic gauge boson couplings at LEP

Abstract The process e + e − →W + W − γ is studied using the data collected by the L3 detector at LEP. New results, corresponding to an integrated luminosity of 427.4 pb −1 at centre-of-mass energies from 192 to 207 GeV, are presented. The W + W − γ cross sections are measured to be in agreement with Standard Model expectations. No hints of anomalous quartic gauge boson couplings are observed. Limits at 95% confidence level are derived using also the process e + e − →ν ν γγ .