The large-$N$ limit of the chiral condensate from twisted reduced models

TL;DR

This paper calculates the large-N limit of the QCD chiral condensate using twisted reduced models on the lattice, employing two methods that yield consistent results in agreement with known SU(3) data.

Contribution

It introduces a novel approach to compute the large-N chiral condensate using twisted reduced models with two independent methods and controlled extrapolations.

Findings

Consistent estimates of the large-N chiral condensate from two methods.

Result matches well with SU(3) FLAG data.

Provides a new lattice-based large-N QCD analysis.

Abstract

We compute the large-$N$ limit of the QCD chiral condensate on the lattice using twisted reduced models, and performing controlled continuum and chiral extrapolations. We perform two different calculations: one consists in extracting the chiral condensate from the quark mass dependence of the pion mass, and the other consists in extracting the chiral condensate from the behaviour of the mode number of the Wilson-Dirac operator for small eigenvalues. We find consistency between the results of the two methods, giving a joint estimate of $\lim_{N\to\infty}\Sigma(N)/N=[184(13)$ MeV$]^3$ ($\overline{\mathrm{MS}}$, $\mu=2$ GeV, taking the square root of the string tension $\sqrt{\sigma}=440$ MeV to set the scale), in remarkable agreement with the $\mathrm{SU}(3)$ 2-flavor FLAG result.