Final State Interactions in Kaon Decays Revisited

We examine the effects of final state interactions (FSI) in kaon decays in a new scheme, in which FSI is described in terms of on-shell quantities instead of the Omnés function, and we show that while it is not possible to explain the ΔI=1/2 rule in terms of FSI alone, the ratio ε′/ε∼16×10−4 is obtained through FSI, if the calculation is restricted to the C P-violating parts. The ππ contribution to the m L-m S mass difference is shown to be about 14%, if the sizes of the CP conserving amplitudes ∣A 0∣ and ∣A 2∣ are correctly given.