VECTOR-MESON EXCHANGE IN RADIATIVE KAON DECAYS AND CHIRAL PERTURBATION-THEORY

The role of vector meson resonances in radiative K decay is analyzed within the context of chiral perturbation theory. In general, there are big cancellations between strong amplitudes with external weak transitions and direct weak amplitudes, which are usually not considered in naive vector meson dominance estimates. We introduce a "weak deformation model" inspired by the geometry of the coset space SU(3)R × SU(3)L/SU(3)V to estimate the direct weak contributions to K → πγ* and K → πγγ. The implications for the decay mode KL → π0e+e- are discussed. © 1990.