Exploring autocorrelations in two-flavour Wilson Lattice QCD using DD-HMC algorithm

TL;DR

This study investigates autocorrelation behaviors of various observables in two-flavour Wilson lattice QCD using the DD-HMC algorithm, revealing how autocorrelations depend on quark mass, lattice spacing, and smearing.

Contribution

It provides a detailed analysis of autocorrelation patterns in lattice QCD with Wilson fermions, highlighting dependencies on physical and simulation parameters.

Findings

Autocorrelation of topological susceptibility decreases with decreasing quark mass at fixed lattice spacing.

Autocorrelation of topological susceptibility increases as lattice spacing decreases.

Larger and more smeared Wilson loops exhibit higher autocorrelation.

Abstract

We perform an extensive study of autocorrelation of several observables in lattice QCD with two degenerate flavours of naive Wilson fermions and unimproved Wilson gauge action using DD-HMC algorithm. We show that (1) at a given lattice spacing, autocorrelation of topological susceptibility decreases with decreasing quark mass and autocorrelations of plaquette and Wilson loop do not increase with decreasing quark mass, (2) autocorrelation of topological susceptibility substantially increases with decreasing lattice spacing but autocorrelation of topological charge density correlator shows only mild increase and (3) increasing the size and the smearing level increase the autocorrelation of Wilson loop.