Operator product expansion and quark condensate from LQCD in coordinate space

TL;DR

This study uses lattice QCD in coordinate space to explore the operator product expansion of the quark propagator, enabling a novel, non-perturbative determination of the quark condensate and quark field renormalization constant.

Contribution

It introduces a new lattice QCD method in coordinate space for extracting the quark condensate and tests OPE predictions non-perturbatively at short distances.

Findings

Quark condensate determined as (-265±5±22 MeV)^3

Quark field renormalization constant Z^MS(2 GeV)=0.871±0.003±0.020

Provides a non-perturbative test of OPE in QCD

Abstract

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.