TY  - JOUR
AU  - Pich, A.
AU  - Rodriguez-Sanchez, A.
PY  - 2021
DA  - 2021//
TI  - SU(3) analysis of four-quark operators: K -> pi pi and vacuum matrix elements
T2  - J. High Energy Phys.
JO  - Journal of High Energy Physics
SP  - 005
EP  - 43pp
VL  - 06
IS  - 6
PB  - Springer
KW  - Chiral Lagrangians
KW  - CP violation
KW  - Effective Field Theories
KW  - Kaon Physics
AB  - 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.
SN  - 1029-8479
UR  - https://arxiv.org/abs/2102.09308
UR  - https://doi.org/10.1007/JHEP06(2021)005
DO  - 10.1007/JHEP06(2021)005
LA  - English
N1  - WOS:000762295200001
ID  - Pich+Rodriguez-Sanchez2021
ER  -