Study of Long Distance Contributions to $K\to n\pi \nu \bar{\nu }$

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

We calculate long distance contributions to $K\to \pi \nu \bar{\nu },\pi \pi \nu \bar{\nu }$, and $\pi \pi \pi \nu \bar{\nu }$ modes within the framework of chiral perturbation theory. We find that these contributions t…