Chiral perturbation theory versus vector meson dominance in the decays φ → ϱγγ and φ → ωγγ

It is pointed out that the radiative decays of a φ meson, φ → ϱγγ and φ → ωγγ, receive dominant contributions from the pseudoscalar (P = η, η′) exchanges. Using the vector meson dominance model, we find that B(φ → ϱγγ) ≈ 1.3 × 10−4 and B(φ → ωγγ) ≈ 1.5 × 10−5, which are mainly from the η′ pole. Thus, these decays are well within the reach of the φ factory. Our estimates are a few orders of magnitude larger than the chiral loop contributions in the heavy vector meson chiral lagrangian, which is about (a few) ×10−9.