2+1 Flavor QCD simulated in the epsilon-regime in different topological sectors

TL;DR

This study compares lattice QCD eigenvalue distributions in different topological sectors with Random Matrix Theory predictions, estimating the chiral condensate with finite size corrections.

Contribution

First comparison of eigenvalue distributions in the epsilon-regime for 2+1 flavor QCD using fixed-point Dirac operator and RMT.

Findings

Eigenvalue distributions match RMT predictions after finite size corrections.

Estimated chiral condensate Sigma(2GeV)^{1/3}=0.239(11) GeV.

Finite size effects are quantitatively accounted for in the analysis.

Abstract

We generated configurations with the parametrized fixed-point Dirac operator D_{FP} on a (1.6 fm)^4 box at a lattice spacing a=0.13 fm. We compare the distributions of the three lowest k=1,2,3 eigenvalues in the nu= 0,1,2 topological sectors with that of the Random Matrix Theory predictions. The ratios of expectation values of the lowest eigenvalues and the cumulative eigenvalue distributions are studied for all combinations of k and nu. After including the finite size correction from one-loop chiral perturbation theory we obtained for the chiral condensate in the MSbar scheme Sigma(2GeV)^{1/3}=0.239(11) GeV, where the error is statistical only.