Studying the scale and q2 dependence of K+→π+e+e− decay

We extract the K+→π+e+e− amplitude scale at q2=0 from the recent Brookhaven E865 high-statistics data. We find that the theoretical long-distance amplitude is in good agreement with the experimental q2=0 scale. Lastly, we find that the observed q2 shape is explained by the combined effect of the pion and kaon form-factor vector-meson-dominance ρ, ω and φ poles, and a charged pion loop coupled to a virtual photon→e+e− transition.