The ${\pi }^0\to e^{+}{e}^{-}$ and $\eta \to {\mu }^{+}{\mu }^{-}$ Decays Revisited

Abstract

The rare ${\pi }^0\to e^{+}{e}^{-}$ and $\eta \to {\mu }^{+}{\mu }^{-}$ 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 $B({\pi }^0\to e^{+}{e}^{-})=(6.41\pm 0.19)\times 10^{-8}$ and $B(\eta \to {\mu }^{+}{\mu }^{-})=(1.14+0.06-0.03)\times 10^{-5}$ in agreement with recent experimental data.

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