QCD Quark Condensate from SUSY and the Orientifold Large-N Expansion

TL;DR

This paper estimates the quark condensate in one-flavor QCD using a novel large-N expansion inspired by SUSY theories, finding results that agree well with lattice and phenomenological data.

Contribution

It introduces a new 'orientifold' large-N expansion method to connect SUSY Yang-Mills results with QCD quark condensates.

Findings

Quark condensate estimate matches lattice QCD results.

The method provides a new way to relate SUSY and non-SUSY gauge theories.

Results are consistent with phenomenological determinations.

Abstract

We estimate the quark condensate in one-flavor massless QCD from the known value of the gluino condensate in SUSY Yang-Mills theory using our newly proposed "orientifold" large-N expansion. The numerical result for the quark condensate renormalized at the scale 2 GeV is then given as a function of alpha_s(2 GeV) and of possible corrections from sub-leading terms. Our value can be compared with the quark condensate in (quenched) lattice QCD or with the one extracted from the Gell-Mann--Oakes--Renner relation by virtue of non-lattice determinations of the quark masses. In both cases we find quite a remarkable agreement.