Rare Kaon Decays in the $1/N_c$-Expansion

Abstract

We study the unknown coupling constants that appear at order $p^4$ in the Chiral Perturbation Theory analysis of $K\to \pi {\gamma }^{\ast }\to \pi l^{+}{l}^{-}$, $K^{+-}\to {\pi }^{+-}\gamma \gamma$ and $K\to \pi \pi \gamma$ decays. To that end, we compute the chiral realization of the $\Delta S=1$ Hamiltonian in the framework of the $1/N_c$-expansion of the low-energy action. The phenomenological implications are also discussed.

Comments: 18 pages, LaTeX, CPT-92/P.2795