Dirac operator spectral density and low energy sum rules

Abstract

The spectral density of euclidean Dirac operator is investigated in partially quenched QCD with arbitrary quark masses. A representation of scalar and pseudoscalar correlators in terms of the spectral density is discussed. The spectral density, obtained from the partially quenched chiral perturbation theory is shown to be compatible with low energy sum rules, obtained earlier.

Comments: 8 pages, latex, published version; NLO QCD correction to the Dirac operator spectral density is added to the text