A data-driven approach to $π^{0}, η$ and $η^{\prime}$ single and double Dalitz decays

Abstract

The dilepton invariant mass spectra and integrated branching ratios of the single and double Dalitz decays $\mathcal{P}\to\ell^{+}\ell^{-}γ$ and $\mathcal{P}\to\ell^{+}\ell^{-}\ell^{+}\ell^{-}$ ($\mathcal{P}=π^{0}, η, η^{\prime}$; $\ell=e$ or $μ$) are predicted by means of a data-driven approach based on the use of rational approximants applied to $π^{0}, η$ and $η^{\prime}$ transition form factor experimental data in the space-like region.