We perform an exploratory study of the operator product expansion of the quark propagator on the lattice at short distance in coordinate space. This permits a simple determination of the quark condensate, <qq>^MS(2 GeV)=(-265\pm 5\pm 22 MeV)^3, and of the renormalization constant of the quark field, Z^MS(2 GeV)=0.871 \pm 0.003 \pm 0.020. This new method also provides a remarkable non-perturbative test of the OPE predictions at short distance in QCD.
@article{arxiv.hep-lat/0510090,
title = {Operator product expansion and quark condensate from LQCD in coordinate space},
author = {V. Gimenez and V. Lubicz and F. Mescia and V. Porretti and J. Reyes},
journal= {arXiv preprint arXiv:hep-lat/0510090},
year = {2007}
}
Comments
6 pp. Talk given at the 23rd International Symposium on Lattice Field Theory: Lattice 2005, Trinity College, Dublin, Ireland, 25-30 July 2005