Anomalous effective lagrangians and vector resonance models

Chiral lagrangians including vector resonances have been shown to saturate the finite part of some of the counterterms needed to regularize ordinary one-loop effective lagrangians of pseudoscalar interactions with external currents. The equivalence between different models has been discussed in the ordinary case. In this paper we extend the analysis to the anomalous sector of chiral lagrangians by comparing the conventional vector model, the 'hidden gauge symmetry' model, where vectors are gauge bosons of a spontaneously broken gauge symmetry, and the model where they are introduced through a tensor field. We find the equivalence works between the last two and that it can be recovered for the first only by including at least scalar resonances in the model. We modify the original formulations of these models by adding a 'minimal coupling' hypothesis which reduces the number of couplings while preserving good agreement with experimental data. Within our scheme, in the absence of chiral breakings and of external axial currents, the anomalous lagrangian can be written in terms of a single known parameter and the saturation hypothesis can be seen to work in the photon-pseudoscalar sector. (orig.)