Quenched chiral logarithms in lattice QCD with overlap Dirac quarks

TL;DR

This paper investigates quenched chiral logarithms in lattice QCD using overlap Dirac quarks, providing precise measurements of the logarithm coefficient and confirming theoretical relations through numerical data.

Contribution

It offers the first detailed numerical determination of quenched chiral logarithm coefficients using overlap Dirac quarks and verifies their consistency with theoretical predictions.

Findings

Determined delta coefficients for various lattice sizes.

Measured index susceptibility and related it to eta' mass.

Found good agreement between different methods of delta estimation.

Abstract

We examine quenched chiral logarithms in lattice QCD with overlap Dirac quarks. From our data of m_pi^2, we determine the coefficient of quenched chiral logarithm delta = 0.203(14), 0.176(17), 0.193(17) and 0.200(13) for lattices of sizes 8^3 times 24, 10^3 times 24, 12^3 times 24 and 16^3 times 32 respectively. Also, for the first three lattice sizes, we measure the index susceptibility of the overlap Dirac operator, and use the exact relation between the index susceptibility and the eta' mass in quenched chiral perturbation theory to obtain an independent determination of delta = 0.198(27), 0.173(24), 0.169(22), which are in good agreement with those determined from m_pi^2.