Exploring chiral dynamics with overlap fermions

TL;DR

This paper reports on a lattice QCD study of chiral symmetry breaking using overlap fermions, demonstrating agreement with chiral perturbation theory and accurately determining the chiral condensate.

Contribution

First lattice study of chiral symmetry breaking with dynamical overlap fermions in fixed topological sectors, confirming theoretical predictions.

Findings

Dirac spectrum matches chiral perturbation theory predictions

Finite size effects are well understood and modeled

Chiral condensate is determined with high accuracy

Abstract

This talk presents a lattice study of spontaneous chiral symmetry breaking performed by the JLQCD and TWQCD collaborations with dynamical overlap fermions. Our lattice configurations are generated in a fixed topological sector. Since finite volume effects, partly due to the fixed global topology, are mainly induced by pion fields, the dependence on the lattice volume, topological charge and quark masses can be analytically predicted using chiral perturbation theory (ChPT). We find a good agreement of Dirac operator spectrum calculated on the lattice with the ChPT prediction including its finite size scalings, through which the chiral condensate is determined with good accuracy.