Concerning the quark condensate
arXiv:nucl-th/0301024 · doi:10.1103/PhysRevC.67.065206
Abstract
A continuum expression for the trace of the massive dressed-quark propagator is used to explicate a connection between the infrared limit of the QCD Dirac operator's spectrum and the quark condensate appearing in the operator product expansion, and the connection is verified via comparison with a lattice-QCD simulation. The pseudoscalar vacuum polarisation provides a good approximation to the condensate over a larger range of current-quark masses.
7 pages, LaTeX2e, revtex4