The Alpha Collaboration has proposed an optimal value for c_SW in the Sheikholeslami-Wohlert action, chosen to remove O(a) effects. To measure hadronic matrix elements to the same accuracy we need a method of finding O(a) improved operators, and their renormalization constants. We determine the Z factors by a non-perturbative method, measuring the matrix elements for single quark states propagating through gauge fields in the Landau gauge. The data show large effects coming from chiral symmetry breaking. This allows us to find the improvement coefficients too, by requiring that the amount of chiral symmetry breaking agrees with that predicted by the chiral Ward identities.
@article{arxiv.hep-lat/9710034,
title = {Non-perturbative improvement and renormalization of lattice operators},
author = {S. Capitani and M. Goeckeler and R. Horsley and H. Oelrich and H. Perlt and D. Pleiter and P. E. L. Rakow and G. Schierholz and A. Schiller and P. Stephenson},
journal= {arXiv preprint arXiv:hep-lat/9710034},
year = {2008}
}
Comments
3 pages, Latex, 2 figures, epsf.sty and espcrc2.sty needed. Talk given at Lattice97