A rational approach to $η$ and $η^\prime$ transition form factors

The $\eta$ and $\eta^\prime$ transition form factors in the space-like region are analyzed at low and intermediate energies in a model-independent way through the use of rational approximants. The slope and curvature parameters of the form factors as well as their values at infinity are extracted from experimental data. The impact of these results on the mixing parameters of the $\eta$-$\eta^\prime$ system are also discussed.