Asymptotical contributions to pion electromagnetic and transition form factor

We present a calculation of the pion electromagnetic and transition from factors in the framework of dispersion relations. At low energies (time-like virtual photon masses), the input in the dispersion relation is obtained by solving the coupled channel problem for the $\pi\pi$ and $K\bar K$ scattering in a fully unitarized K-matrix approach. At high energies, we propose a model that features novel colored Regge exchange contributions. The parameters of these Regge exchanges can be related to the high energy behavior of meson-meson scattering amplitudes. The recent data on the transition $\gamma^*\to\pi^0\gamma$ form factor by BaBar collaboration can be explained in our model with no further adjustments.