The $π^0\to e^+e^-$ and $η\to μ^+ μ^-$ Decays Revisited

Abstract

The rare $π^0 \to e^+e^-$ and $η\to μ^+μ^-$ decays are calculated in different schemes, which are seen to be essentially equivalent to and produce the same results as conventional Vector-Meson Dominance. We obtain the theoretical predictions $B(π^0 \to e^+e^-) = (6.41 \pm 0.19)\times 10^{-8}$ and $B(η\to μ^+μ^-) = (1.14 +0.06 -0.03) \times 10^{-5}$ in agreement with recent experimental data.

10 pages, LATEX (revised version for recent experimental data)