Vector meson exchange and radiative nonleptonic kaon decays in ChPT

Abstract

ChPT is a powerful tool to study low energy pseudoscalar mesons physics. After a short introduction to ChPT in chapter 1 and its application to radiative nonleptonic Kaon decays in chapter 2, we studied the contribution of vector meson exchang to the specific decay $K_S\rightarrow \pi^0 \pi^0 \gamma \gamma$. We fixed two coupling coefficients of $\mathcal{O}(p^6)$ weak effective chiral Lagrangian by using Bose symmetry, gauge symmetry and two bound equations got from experiment NA48. We show that vector meson exchange in weak sector is dominant at $\mathcal{O}(p^6)$, and its contribution cancels the biggest contribution at $\mathcal{O}(p^4)$ about 60%.