Search for anomalous ZZγ and Zγγ couplings with D0

A direct test of the Standard Model by searching for anomalous ZZγ and Zγγ couplings is presented. The authors analyze p bar p → llγ + X, (l = e,μ) events at √s = 1.8 TeV with the D0d detector at the Fermilab Tevatron Collider. A fit to the transverse energy spectrum of the photon in the signal events, based on the data set corresponding to an integrated luminosity of 13.9 pb-1 (13.3 pb-1) for the electron (muon) channel, yields the following 95% CL limits on the anomalous CP-conserving ZZγ couplings: -1.9 < h30Z < 1.8 (h40Z = 0), and -0.5 < h40Z < 0.5 (30Z = 0), for a form-factor scale Λ = 500 GeV. Limits on the Zγγ couplings and CP-violating couplings are also discussed