Single and double Dalitz decays of π0, η and η′ mesons

We analyze the single and double Dalitz decays, P→ℓ+ℓ−γ and P→ℓ+ℓ−ℓ+ℓ−(P=π0,η,η′;ℓ=eorμ), benefited from fitting, through the use of Padé approximants, the current experimental data on the transition form factors γ⁎γ→P in the spacelike energy region to describe the timelike P→γ⁎γ(⁎) reactions. Predictions for the mass spectra and branching ratios are given and compared with their present experimental status.