Some peculiarities of the π0→e+e- amplitude are discussed. The equivalence between vector meson dominance and quark models is clearly established (Q2 duality). The relevant mass scales in that decay imply some universal properties for the amplitude. The braching ratio Bπ≡ Γ(π0→e+e-) Γ(π0→γγ) depends only on a characteristic cut-off and not on the details of the models. Our model-insensitive prediction is Bπ∼6×10-8, far below the experimental data. © 1983.
|Journal||Physics Letters B|
|Publication status||Published - 23 Jun 1983|