Zero temperature string breaking in lattice quantum chromodynamics - art. no. 074509

The separation of a heavy quark and antiquark pair leads to the formation o f a tube of flux, or "string," which should break in the presence of light quark-antiquark pairs. This expected zero-temperature phenomenon has proven elusive in simulations of lattice QCD. We study mixing between the string state and the two-meson decay channel in QCD with two flavors of dynamical sea quarks. We confirm that mixing is weak and find that it decreases at le vel crossing. While our study does not show direct effects of internal quar k loops, our results, combined with unitarity, give a clear confirmation of string breaking.