Short distance current correlators: Comparing lattice simulations to the instanton liquid - art. no. 094508

Point to point correlators of currents arc computed in quenched QCD using a chiral lattice fermion action, the overlap action. I compare correlators m ade of exact quark propagators with correlators restricted to low (less tha n 500 MeV) eigenvalue eigenmodes of the Dirac operator. In many cases they show a qualitative resemblance (typically at small values of the quark mass and distances larger than 0.4 fm) and they differ qualitatively at larger quark masses or at very short distance. Lattice results are in qualitative agreement (and in the difference of vector and axial vector channels, quant itative agreement) with the expectations of instanton liquid models. The sc alar channel shows the effects of a quenched finite volume zero mode artifa ct, a negative correlator.