Comparison between overlap and twisted mass fermions towards the chiral limit

TL;DR

This study compares overlap and twisted mass fermions in lattice QCD to evaluate their effectiveness in approaching the chiral limit, measuring hadron properties at a fixed lattice spacing.

Contribution

It provides a direct comparison of chirally invariant overlap fermions and Wilson twisted mass fermions near the chiral limit in quenched simulations.

Findings

Both formulations reach pion masses of about 250 MeV.

Measurements include hadron masses and decay constants.

Simulations conducted at a fixed lattice spacing of 0.123 fm.

Abstract

We compare overlap fermions, which are chirally invariant, and Wilson twisted mass fermions in the approach to the chiral limit. Our quenched simulations reveal that with both formulations of lattice fermions pion masses of O(250 MeV) can be reached in practical simulations. Our comparison is done at a fixed lattice spacing a=0.123 fm. Several quantities are measured, such as hadron masses and pseudoscalar decay constants.