The decay $K_L$→${\pi }^0$$e^{+}$$e^{\mathrm{-}}$ can proceed through a CP-violating amplitude of order $G_F$${\alpha }_{\mathrm{em}\mathrm{\epsilon }}$ or a CP-conserving amplitude of order $G_F$${\alpha }_{\mathrm{em}{}^2}$. The latter is shown to be significant, and probably the dominant contribution. Interference of the two pieces produces a large asymmetry between the $e^{+}$ and $e^{\mathrm{-}}$ energy spectra. Some comments are made on the e:μ ratio in $K_L$→${\pi }^0$$l^{+}$$l^{\mathrm{-}}$. .AE

• Received 8 March 1988

DOI:https://doi.org/10.1103/PhysRevD.38.808