K → πππ decays in large Nc chiral perturbation theory

Abstract

Corrections to the current-algebra analysis of ΔI = 1 2 and 3 2 K → πππ decay amplitudes including K s→ π + π − π 0 are calculated using the large N c higher-order effective chiral lagrangians for strong and weak interactions. Neglecting gluonic corrections to the coupling constants of the higher-derivative chiral lagrangians, we find an agreement between theory and experiment within 30% for the constant and linear terms of ΔI = 1 2 transitions. Quadratic coefficients of various ΔI = 3 2 amplitudes in the Dalitz plot are predicted. The branching ratio and the slope parameter of K s → π + π − π 0 are found to be 3.9 × 10 −7 and 4.4 × 10 −2, respectively.