Non-leptonic kaon decays and the chiral anomaly

Abstract

An investigation is performed of all non-leptonic kaon decays sensitive to the chiral anomaly. Within the framework of chiral perturbation theory, there are two classes of anomalous amplitudes at O(p4): reducible and direct contributions. Only radiative transitions are affected by the anomaly. The phenomenology of the decays KL → π+π−γ and K+ → π+π0γ is studied in detail. Including the dominant contributions of O(p6), the experimentally observed dependence of he direct emission amplitude for KL → π+π−γ on the photon energy can be understood. A survey is made of the rare “anomalous” decays K → ππγγ and K → 3πγ (γ), including some numerical estimates.