We introduce a new parameterization of four-fermion matrix elements which does not involve quark masses and thus allows a reduction of systematic uncertainties in physical amplitudes. As a result the apparent quadratic dependence of e'/e on m_s is removed. To simplify the matching between lattice and continuum renormalization schemes, we express our results in terms of Renormalization Group Invariant B-parameters which are renormalization-scheme and scale independent. As an application of our proposal, matrix elements of DeltaI=3/2 and SUSY DeltaF=2 (F=S,C,B) four-fermion operators have been computed.
@article{arxiv.hep-lat/9909041,
title = {Matrix Elements without Quark Masses on the Lattice},
author = {A. Donini and V. Gimenez and L. Giusti and G. Martinelli},
journal= {arXiv preprint arXiv:hep-lat/9909041},
year = {2015}
}