Additional isospin-breaking effects in implied by'/implied by

摘要

In the analysis of implied by'/implied by it has been traditional to consider the isospin-breaking effects arising from electroweak-penguin contributions and from #pi#~0 -#eta#,#eta#' mixing, yet additional isospin-violating effects exist. In particular, we study the isospin violation which arises from the u-d quark mass difference in the hadronization of the gluonic penguin operator, engendering contributions of an effective #DELTA#I = 3/2 character. Using chiral perturbation theory and the factorization approximation for the hadronic matrix elements, we find within a specific model for the low-energy constants that we can readily accommodate an increase in implied by'/implied by by a factor of two.