The e+e- -> Z gamma gamma -> q q gamma gamma Reaction at LEP and Constraints on Anomalous Quartic Gauge Boson Couplings
arXiv:hep-ex/0206050 · doi:10.1016/S0370-2693(02)02127-5
Abstract
The cross section of the process e^+ e^- -> Z γγ-> qq γγis measured with 215 pb^-1 of data collected with the L3 detector during the final LEP run at centre-of-mass energies around 205 GeV and 207 GeV. No deviation from the Standard Model expectation is observed. The full data sample of 713 pb^-1, collected above the Z resonance, is used to constrain the coefficients of anomalous quartic gauge boson couplings to: -0.02 GeV^-2 < a_0/Λ^2 < 0.03 GeV^-2 and -0.07 GeV^-2 < a_c/Λ^2 < 0.05 GeV^-2, at 95% confidence level.