need to fix an upper energy bound (as it was said $E_{\rm
max}=1.5 TeV$) so that we can safely apply $\chi PT$.

However, the $ET$ can be used as a helpful tool to test our calculated longitudinally polarized amplitudes. In order to check our results we have compared our tree level expressions with those calculated applying the $ET$ to the corresponding Goldstone boson amplitudes. We have found both amplitudes to agree at lowest order in $g$ and $g'$ for the cases $Z^0_LZ^0_L \rightarrow Z^0_LZ^0_L$, $W^+_LW^-_L \rightarrow Z^0_LZ^0_L$ and $W^{\pm}_LZ^0_L \rightarrow
W^{\pm}_LZ^0_L$ as it was expected according to the results of [@ETCL]. However, the details of this comparison will be described in detail elsewhere [@GLASGOW] since they concern the applicability of the $ET$ which has not been used in the present computation. Here we only wanted to quote that our results are compatible with the information that one could have obtained from the $ET$ on the above mentioned processes.

Signatures and background
=========================

As it was stressed in the previous section we have calculated the tree level scattering amplitudes, up to order $p^4$, corresponding to all the helicity states of the gauge bosons, without using the $ET$. This fact allows us 