Paper

Detecting the flavor content of the vacuum using the Dirac operator spectrum

Liu, Keh-Fei, Yu-Jiang, Bi, Yi-Bo, Yang, Draper, Terrence, Andrei Alexandru, Liang, Jian

2024

Overview

We compute the overlap Dirac spectrum on three gauge ensembles generated using \\(2+1\\)-flavor domain wall fermions. The three ensembles have different lattice spacings and two of them have quark masses tuned to the physical point. The spectral density is determined up to \\(\\lambda\\sim\\)100 MeV with subpercentage statistical uncertainty. We find that the density is close to a constant below \\(\\lambda\\sim\\) 20 MeV as predicted by chiral perturbative theory (\\(\\chi\\)PT), and then increases linearly due to the strange quark mass. By fitting to the next-to-leading order \\(\\chi\\)PT form and using the non-perturbative RI/MOM renormalization, the \\(\\rm SU(2)\\) (keeping the strange quark mass at the physical point) and \\(\\rm SU(3)\\) chiral condensates at \\(\\overline{\\textrm{MS}}\\) 2 GeV are determined to be \\(\\Sigma=(265.4(0.5)(4.2)\\ \\textrm{MeV})^3\\) and \\(\\Sigma_0=(234.3(0.5)(25.8)\\ \\textrm{MeV})^3\\), respectively. The pion decay constants are also determined to be \\(F=84.1(1.9)(8.0)\\) and \\(F_0=58.6(0.5)(10.0)\\) MeV. The systematic errors are carefully estimated including the effects of fitting ranges and the uncertainty of low-energy constant \\(L_6\\). We also show that one can resolve the sea flavor content of the sea quarks and constrain their masses with {\\(\\sim10\\%-20\\%\\)} statistical uncertainties using the Dirac spectral density.

• Publisher: Cornell University Library, arXiv.org
• Subject: Domain walls / Eigenvalues / Fermions / Flavor (particle physics) / Quarks / Uncertainty