Meson and baryon masses with low mode averaging

TL;DR

The paper investigates low mode averaging in lattice QCD to enhance two-point function calculations, comparing hermitian and non-hermitian eigenmodes, with results varying by state parity.

Contribution

It introduces and tests a low mode averaging method for lattice QCD two-point functions, analyzing the effects of using different eigenmodes and state parity.

Findings

Low mode averaging improves two-point function signals.

Convergence depends on the parity of the states.

Eigenmode choice influences the effectiveness of the method.

Abstract

We describe and test a method known in the literature as low mode averaging to improve Euclidean two-point functions in lattice QCD using the low-lying eigenmodes of the Wilson-Dirac operator D. The contribution from the low modes is averaged over all positions of the quark sources while the contribution from high modes is calculated in the traditional way using one source point per lattice. We apply this method to different baryon and meson two-point functions and we compare the improvements using the eigenmodes of the non-hermitian operator D and the eigenmodes of the hermitian operator Q=gamma5 D. The convergence strongly depends on the parity of the states.