String Breaking in Four Dimensional Lattice QCD

TL;DR

This paper investigates string breaking in four-dimensional lattice QCD by using the truncated determinant algorithm to include dynamical quark effects, revealing evidence of string tension flattening at large distances.

Contribution

It demonstrates the first evidence of string breaking in unquenched 4D lattice QCD using TDA with low quark mass on large lattices.

Findings

Evidence of string tension flattening at R ≥ 1 fm

Successful application of TDA in unquenched lattice QCD

Analysis of Wilson line correlators supports string breaking

Abstract

Virtual quark pair screening leads to breaking of the string between fundamental representation quarks in QCD. For unquenched four dimensional lattice QCD, this (so far elusive) phenomenon is studied using the recently developed truncated determinant algorithm (TDA). The dynamical configurations were generated on an Athlon 650 MHz PC. Quark eigenmodes up to 420 MeV are included exactly in these TDA studies performed at low quark mass on large coarse (but O($a^2$) improved) lattices. A study of Wilson line correlators in Coulomb gauge extracted from an ensemble of 1000 two-flavor dynamical configurations reveals evidence for flattening of the string tension at distances R $\geq$ approximately 1 fm.