Spectral density of the Dirac operator in two-flavour QCD

Abstract

We compute the spectral density of the (Hermitean) Dirac operator in Quantum Chromodynamics with two light degenerate quarks near the origin. We use CLS/ALPHA lattices generated with two flavours of O(a)-improved Wilson fermions corresponding to pseudoscalar meson masses down to 190 MeV, and with spacings in the range 0.05-0.08 fm. Thanks to the coverage of parameter space, we can extrapolate our data to the chiral and continuum limits with confidence. The results show that the spectral density at the origin is non-zero because the low modes of the Dirac operator do condense as expected in the Banks-Casher mechanism. Within errors, the spectral density turns out to be a constant function up to eigenvalues of approximately 80 MeV. Its value agrees with the one extracted from the Gell-Mann-Oakes-Renner relation.

References in corpus (5)

• Critical slowing down and error analysis in lattice QCD simulations
• Chiral symmetry breaking and the Banks--Casher relation in lattice QCD with Wilson quarks
• Topological susceptibility and the sampling of field space in $N_f=2$ lattice QCD simulations
• Chiral symmetry breaking in QCD Lite
• Comparison of the mass preconditioned HMC and the DD-HMC algorithm for two-flavour QCD

Cited by in corpus (5)

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• Chiral symmetry breaking in QCD Lite
• Dark matter relic density in strongly interacting dark sectors with light vector mesons
• Stochastic calculation of the Dirac spectrum on the lattice and a determination of chiral condensate in 2+1-flavor QCD
• Impact of Dynamical Charm Quark and Mixed Action Effect on Light Hadron Masses and Decay Constants