Using chiral Ward identities, we determine the renormalisation constants of bilinear quark operators for the Sheikholeslami-Wohlert action lattice at beta=6.2. The results are obtained with a high degree of accuracy. For the vector current renormalisation constant we obtain Z_V=0.817(2)(8), where the first error is statistical and the second is due to mass dependence of Z_V. This is close to the perturbative value of 0.83. For the axial current renormalisation constant we obtain Z_A = 1.045(+10 -14), significantly higher than the value obtained in perturbation theory. This is shown to reduce the difference between lattice estimates and the experimental values for the pseudoscalar meson decay constants, but a significant discrepancy remains. The ratio of pseudoscalar to scalar renormalisation constants, Z_P/Z_S, is less well determined, but seems to be slightly lower than the perturbative value.
@article{arxiv.hep-lat/9412088,
title = {Current Renormalisation Constants with an O(a)-improved Fermion Action},
author = {David Henty and Richard Kenway and Brian Pendleton and Jon Ivar Skullerud},
journal= {arXiv preprint arXiv:hep-lat/9412088},
year = {2009}
}
Comments
8 pages uuencoded compressed postscript file. Article to be submitted to Phys.Rev.D