Meson-gluon interaction and ΔI=1/2 problem in the standard model

Summary

In the present paper we study the new K→ππ decay channel with the gluons being an intermediate state which is neglected within the factorization framework. Both short-distance (perturbative) and long-distance (non-perturbative) part of the corresponding amplitude are calculated To obtain the long-distance contribution the chiral Lagrangian approach is used as a low-energy model of strong interactions and a relevant chiral coupling is derived via QCD sum rules. We find that non-perturbative contribution being dominant, gives additional enhancement of the K→ππ decay amplitude with the isospin transfer ΔI=1/2 what improves the rather undetermined situation with the ΔI=1/2 problem. The scale of this new contribution allows us to conclude that there is a sizable violation of the factorization hypothesis in theO(p ⁴) order of the chiral expansion.