Gribov noise on the lattice axial current renormalisation constant

Renormalisation on the Penrose Lattice

Non-perturbative determination of the axial current normalization constant in O(a) improved lattice QCD

A finite-size technique is employed to compute the normalization constant ZA of the isovector axial current in lattice QCD. The calculation is carried out in the quenched approximation for values of the bare gauge coupling g0 ranging from 0 to 1. In the lattice action and the lattice expression for the axial current we include the counterterms required for O(a) improvement, with non-perturbativ...

Axial vector current of exact chiral symmetry on the lattice

We discuss the exact chiral symmetry and its spontaneous breakdown in lattice QCD with the Dirac operators satisfying the GinspargWilson relation. The axial vector current, which turns out to be related to the vector current simply by the insertion of the operator γ5(1−aD), is explicitly constructed in the case of the Neuberger-Dirac operator. We also consider an Euclidean proof of the Nambu-Go...

The Gluon Propagator without lattice Gribov copies

We study the gluon propagator on the lattice using the Laplacian gauge which is free of lattice Gribov copies. We compare our results with those obtained in the Landau gauge on the lattice, as well as with various approximate solutions of the Dyson Schwinger equations. We find a finite value ∼ (250MeV)−2 for the zero-momentum propagator, and a pole mass ∼ 640± 110 MeV.

Gribov Copies in Lattice QCD

We have performed an exhaustive search for Gribov copies on the lattice and their possible dependence from finite temperature effects. We show that, for each value of lattice size, Gribov copies are dense in configuration space at low temperature but their density tend to lower when the temperature increases. We have investigated lattice sizes running from 163 × 8 to 164. Gribov [1] has shown t...