String breaking in four dimensional lattice QCD - art. no. 111501

Virtual quark pair screening leads to breaking of the string between fundam ental representation quarks in QCD. For unquenched four dimensional lattice QCD, this (so far elusive) phenomenon is studied using the recently develo ped truncated determinant algorithm (TDA). The dynamical configurations wer e generated on a 650 MHz PC. Quark eigenmodes up to 420 MeV are included ex actly 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 configuration s reveals evidence for flattening of the string tension at distances R grea ter than or similar to1 fm.