Two-flavor lattice QCD in the regime and chiral random matrix theory
Journal
Physical Review D - Particles, Fields, Gravitation and Cosmology
Journal Volume
76
Journal Issue
5
Date Issued
2007
Author(s)
Fukaya, H.
Aoki, S.
Hashimoto, S.
Kaneko, T.
Matsufuru, H.
Noaki, J.
Ogawa, K.
Onogi, T.
Yamada, N.
Abstract
The low-lying eigenvalue spectrum of the QCD Dirac operator in the regime is expected to match with that of chiral random matrix theory (ChRMT). We study this correspondence for the case including sea quarks by performing two-flavor QCD simulations on the lattice. Using the overlap fermion formulation, which preserves exact chiral symmetry at finite lattice spacings, we push the sea quark mass down to ∼3MeV on a 163×32 lattice at a lattice spacing a0.11fm. We compare the low-lying eigenvalue distributions and find a good agreement with the analytical predictions of ChRMT. By matching the lowest-lying eigenvalue we extract the chiral condensate, ΣMS̄(2GeV)= (251±7±11MeV)3, where errors represent statistical and higher order effects in the expansion. We also calculate the eigenvalue distributions on the lattices with heavier sea quarks at two lattice spacings. Although the expansion is not applied for those sea quarks, we find a reasonable agreement of the Dirac operator spectrum with ChRMT. The value of Σ, after extrapolating to the chiral limit, is consistent with the estimate in the regime. © 2007 The American Physical Society.
SDGs
Type
journal article