2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/140037Contrary to wide-spread opinion that the final state interaction (FSI) enhances the amplitude <2π;I=0|K^0>, we argue that FSI does not increase the absolute value of this amplitude.8 pagesHigh Energy Physics - PhenomenologyFinal state interaction and ΔI=1/2 ruletext