Quartic anomalous couplings at LEP

The search for quartic anomalous gauge couplings at LEP requires appropriate predictions for the radiative processes e(+)e(-) --> nu<(<nu>)over bar>gamma gamma, e(+)e(-) --> q (q) over bar gamma gamma and e(+)e(-) --> 4 fermions +gamma. Matrix elements are exactly computed at the tree level, and the effects of anomalous couplings and initial-state radiation are included. Comparisons with results and approximations existing in the literature are shown and commented. Improved versions of the event generators NUNUGPV and WRAP are made available for experimental analysis. (C) 2001 Published by Elsevier Science B.V.