Egalitarian Improvement to Democracy: Quark renormalization constants in N_f=2 QCD

TL;DR

This paper reports on the non-perturbative calculation of quark field renormalization constants in lattice QCD, addressing lattice artifacts and confirming the presence of a gluon condensate.

Contribution

It provides a detailed non-perturbative evaluation of $Z_q$ in Landau gauge using multiple lattice spacings, highlighting lattice artifacts and gluon condensate effects.

Findings

Confirmation of the gluon condensate presence

Isolation of lattice artifacts from perturbative and non-perturbative sources

Non-perturbative $Z_q$ results across three lattice spacings

Abstract

We present our results on the non-perturbative evaluation of the renormalization constant for the quark field, $Z_q$, in Landau gauge within RI-MOM scheme. Using three lattice spacing we are able to isolate lattice artefacts of various origin, both perturbative and non-perturbative. In particular, the existence of the dimension-two gluon-condensate is discussed, and confirmed.