CP Conserving and Violating Contributions to $K_L\to {\pi }^{+}{\pi }^{-}\nu \bar{\nu }$

C. Q. Geng, I. J. Hsu, Y. C. Lin

We study both CP conserving and violating contributions to the decay $K_L\to {\pi }^{+}{\pi }^{-}\nu \bar{\nu }$. We find that the decay branching ratio is dominated by the CP conserving part. In the sta…