Limits on the anomalous ZZ(gamma) and Z(gamma)(gamma) couplings in p(anti p) collisions at (radical)s = 1.8 TeV

摘要

The authors performed a direct search for the anomalous ZZ(gamma) and Z(gamma)(gamma) couplings by studying p(anti p) (yields) (ell)(ell)(gamma) + X, ((ell) = e, (mu)) events at (radical)s = 1.8 TeV with the D0 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 14.3 pb(sup (minus)1) (13.7 pb(sup (minus)1)) for the electron (muon) channel, yields the following 95% confidence level limits on the anomalous CP-conserving ZZ(gamma) couplings: (vert bar)h(sub 30)(sup Z)(vert bar) < 1.8 (h(sub 40)(sup Z) = 0), and (vert bar)h(sub 40)(sup Z)(vert bar) < 0.5 (h(sub 30)(sup Z) = 0), for a form-factor scale (Lambda) = 500 GeV. Limits for the Z(gamma)(gamma) couplings and CP-violating couplings are also discussed.