2018/11/16 by Sánchez, Antonio Rodríguez, Pich, Antonio
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.1811.06706
In the chiral limit, the D=6 contribution to the Operator Product Expansion (OPE) of the VV-AA correlator of quark currents only depends on two vacuum condensates, which can be related to hadronic matrix elements associated to CP violation in non-leptonic kaon decays. We use those relations to determine ⟨(ππ)I=2|Q8|K⟩, using the updated ALEPH spectral functions. Alternatively, we use those relations in the opposite direction. Taking the values of the matrix elements from the lattice to obtain the D=6 vacuum elements provides a new short-distance constraint which allows for an inclusive determination of fπ and an updated value for the D=8 condensate.