6533b7d0fe1ef96bd125abae

RESEARCH PRODUCT

The decays K→πl+l− beyond leading order in the chiral expansion

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We present a model-independent analysis of K+→π+l+l− and KS→π0l+l− decays, including K→3π unitarity corrections and a general decomposition of the dispersive amplitude. From the existing data on K+→π+e+e− we predict the ratio R = B(K+→π+μ+μ−)/B(K+→π+e+e−) to be larger than 0.23, in slight disagreement with the recent measurement R = 0.167±0.036. Consequences for the K±→π±e+e− charge asymmetries and for the KL→π0e+e− mode are also discussed.