%0 Journal Article
%T SU(3) analysis of four-quark operators: K -> pi pi and vacuum matrix elements
%A Pich, A.
%A Rodriguez-Sanchez, A.
%J Journal of High Energy Physics
%D 2021
%V 06
%N 6
%I Springer
%@ 1029-8479
%G English
%F Pich+Rodriguez-Sanchez2021
%O WOS:000762295200001
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5148), last updated on Sun, 13 Mar 2022 18:16:45 +0000
%X Hadronic matrix elements of local four-quark operators play a central role in non-leptonic kaon decays, while vacuum matrix elements involving the same kind of operators appear in inclusive dispersion relations, such as those relevant in tau -decay analyses. Using an SU(3)(L) circle times SU(3)(R) decomposition of the operators, we derive generic relations between these matrix elements, extending well-known results that link observables in the two different sectors. Two relevant phenomenological applications are presented. First, we determine the electroweak-penguin contribution to the kaon CP-violating ratio epsilon '/epsilon, using the measured hadronic spectral functions in tau decay. Second, we fit our SU(3) dynamical parameters to the most recent lattice data on K -> pi pi matrix elements. The comparison of this numerical fit with results from previous analytical approaches provides an interesting anatomy of the Delta I = 1/2 enhancement, confirming old suggestions about its underlying dynamical origin.
%K Chiral Lagrangians
%K CP violation
%K Effective Field Theories
%K Kaon Physics
%R 10.1007/JHEP06(2021)005
%U https://arxiv.org/abs/2102.09308
%U https://doi.org/10.1007/JHEP06(2021)005
%P 005-43pp