CP-Conserving Contribution in the Decays KL-> and KL-> e+ e-

Abstract

The CP-conserving contribution to the decay KL →π° e+e- is reexamined. The general form of the decay rates for KL→π° γγ and KL→π° γγ→π° e+e- (the absorptive part) is obtained. Using the vector meson dominance (VMD) model, the branching ratios for KL→π° γγ and KL→π° γγ→π° e+e- (the absorptive part) are shown to be Br[ KL →π° e+e- ]|2r ≥1.7 ×10-11, Br[ KL →π° γγ] = 1.4 ×10-6. Our result suggests that the CP-conserving contribution with VMD model may be larger than the CP-violating one in the standard model.