Are V→ Pγ decays too small for the quark model?

Abstract

It is shown that the considerably reduced widths found recently in V→P_γ transitions are accountable via the recoil effect under the quark-pair-creation hypothesis which gives a parameter-free reduction factor (⅔)². However, the problems of ω→π⁰γ and Δ→N_γ seem to remain, so direct Primakoff-type measurements via ω and Δ⁰ production with π⁰ and neutron beams, respectively, on nuclei are suggested to resolve the issue.