Vacuum Insertion Method from Chiral Nc \to \infty Approach for the \Delta S = 1 Effective Hamiltonian

Abstract

We check to what extent the assumptions of the vacuum insertion method, as used in the theory o f K —* tttt decays, can be derived from the high N c approximation to the chiral perturbation theory. We find that, besides the well-known problem of Fierz terms, only the assumption for the K 13 formfactor ( /_ = 0) does not follow. This assumption, however, affects the penguin contributions by less than four per cent and the nonpenguin contributions by less than two percent[…]