Su(L)(2) x U(Y)(1)-invariant description of the bilepton contribution to the WWV vertex in the minimal 331 model

We study the one-loop sensitivity of the WWV (V={gamma},Z) vertex to the new massive gauge bosons predicted by the minimal SU{sub L}(3)xU{sub X}(1) model, which have unusual couplings to the standard model (SM) gauge bosons. A gauge-fixing procedure covariant under the SU{sub L}(2)xU{sub Y}(1) group was introduced for these new gauge bosons (dubbed bileptons) in order to generate gauge-invariant Green functions. The similarities between this procedure and the unconventional quantization scheme of the background field method are discussed. It is found that, for relatively light bileptons, with a mass ranging from 2m{sub W} to 6m{sub W}, the radiative corrections to the form factors associated with the WWV vertex can be of the same order of magnitude than the SM one. In the case of heavier bileptons, their contribution is smaller by about one and 2 orders of magnitude than their SM counterpart.