Hadron spectrum, quark masses and decay constants from light overlap fermions on large lattices

TL;DR

This paper reports on lattice QCD simulations using overlap fermions to calculate hadron spectra, quark masses, and decay constants, analyzing finite volume and lattice spacing effects, and comparing results with chiral perturbation theory.

Contribution

First large-scale quenched overlap fermion simulations on extensive lattices with nonperturbative renormalization and comparison to chiral perturbation theory.

Findings

Accurate hadron mass calculations down to 250 MeV pion mass.

Nonperturbative renormalization of scalar and axial currents.

Consistent scaling behavior across different lattice spacings.

Abstract

We present results from a simulation of quenched overlap fermions with L\"uscher-Weisz gauge field action on lattices up to $24^3 48$ and for pion masses down to $\approx 250$ MeV. Among the quantities we study are the pion, rho and nucleon masses, the light and strange quark masses, and the pion decay constant. The renormalization of the scalar and axial vector currents is done nonperturbatively in the $RI-MOM$ scheme. The simulations are performed at two different lattice spacings, $a \approx 0.1$ fm and $\approx 0.15$ fm, and on two different physical volumes, to test the scaling properties of our action and to study finite volume effects. We compare our results with the predictions of chiral perturbation theory and compute several of its low-energy constants. The pion mass is computed in sectors of fixed topology as well.