so called Equivalence Theorem ($ET$) [@ET]. This theorem relates the $S$ matrix elements of processes containing electroweak gauge bosons $LC$ with the corresponding processes with $GB$. However, in a recent work [@ETCL] concerning the formulation of the $ET$ in the context of $\chi PT$, the Equivalence Theorem is severely restricted to a narrow energy applicability window. It can also be applied in the high energy domain together with the $\chi PT$ but using some non-perturbative technique, like dispersion relations [@Uni] or the large $N$ limit [@largeN], in order to have an appropriate unitarity behaviour of the amplitudes.

For this reason we consider prioritary to apply directly the chiral Lagrangian description of the $ESB$ without using the $ET$. The main problems of this approach are two: First one has to include explicitly the gauge degrees of freedom in the model which makes the computations extremely more difficult. Second, one has to restrict the results to the low energy region where standard $\chi PT$ can safely be applied thus losing many higher energy events. The advantage is that the values of the fitted parameters will be more reliable since one is not using the $ET$ complemented with some non-perturbative method.

The plan 