KL → π0γγ and relate decays

This paper presents a phenomenological review of the decay KL → π0γγ, through the two dominant contributions of the π loop and vector meson dominance mechanisms. We have paid particular attention to consistency on the one hand between recent experimental measurements and theoretical models of KL → π0γ γ decay and on the other hand between KL → π0 γγ and other rather similar decays as KS → γγ, KL → γγ and μ → π0γγ