Probing anomalous quartic gauge-boson couplings via e+e- → 4 fermions+γ

All lowest-order amplitudes for e(+)e(-)--> 4f gamma are calculated including five anomalous quartic gauge-boson couplings that are allowed by electromagnetic gauge invariance and the custodial SU(2)(c) symmetry. Three of these anomalous couplings correspond to the operators L-o, L-c, and L-n, that have been constrained by the LEP collaborations in WW theta production. The anomalous couplings are incorporated in the Monte Carlo generator RACOONWW(1). Moreover, for the processes e(+)e(-)--> 4f gamma RACOONWW is improved upon including leading universal electroweak corrections such as initial-state radiation. The discussion of numerical results illustrates the size of the leading corrections as well as the impact of the anomalous quartic couplings for LEP2 energies and at 500 GeV.