Estimate of the chiral condensate in quenched lattice QCD

We determine the value of the quark condensate from quenched QCD simulations on the lattice in two ways: (i) by using the Gell-Mann-Oakes-Renner (GMOR) formula; (ii) by comparing the OPE prediction for the Goldstone pole contribution to the pseudoscalar vertex, at moderately large momenta. In the MS scheme at mu = 2 GeV, from the GMOR formula we obtain (qq) = - (273 +/- 19 MeV)(3). We show that the value extracted from the pseudoscalar vertex, (qq) (312 +/- 24 MeV)(3), although larger, is consistent with the result obtained from the first (standard) method. (C) 2004 Published by Elsevier B.V.