The chiral condensate of $N_f=2+1$ QCD from the spectrum of the staggered Dirac operator

TL;DR

This paper calculates the chiral condensate in 2+1 QCD using lattice simulations of the staggered Dirac operator, employing multiple methods to ensure reliable results aligned with phenomenology.

Contribution

It introduces a comprehensive approach combining spectral and topological methods to determine the chiral condensate in 2+1 QCD with controlled extrapolations.

Findings

Consistent chiral condensate values across different methods.

Results agree with phenomenological estimates.

Validated lattice discretization approaches.

Abstract

We compute the chiral condensate of $2+1$ QCD from the mode number of the staggered Dirac operator, performing controlled extrapolations to both the continuum and the chiral limit. We consider also alternative strategies, based on the quark mass dependence of the topological susceptibility and of the pion mass, and obtain consistent results within errors. Results are also consistent with phenomenological expectations and with previous numerical determinations obtained with different lattice discretizations.