Quenched twisted mass QCD at small quark masses and in large volume

TL;DR

This paper tests quenched twisted mass QCD at small quark masses and large volumes, demonstrating its effectiveness in computing meson properties with manageable computational costs and minimal scaling violations.

Contribution

It provides non-perturbative O(a) improved meson mass and decay constant calculations in quenched twisted mass QCD at small quark masses and large volumes, with analysis of scaling violations.

Findings

Accurate meson masses and decay constants down to low quark masses.

Absence of exceptional configurations in the simulations.

CPU time cost comparable to Wilson quarks at similar quark mass ratios.

Abstract

As a test of quenched lattice twisted mass QCD, we compute the non-perturbatively O($a$) improved pseudoscalar and vector meson masses and the pseudoscalar decay constant down to $M_{\rm PS}/M_{\rm V} = 0.467(13)$ at $\beta=6$ in large volume. We check the absence of exceptional configurations and -- by further data at $\beta=6.2$ -- the size of scaling violations. The CPU time cost for reaching a given accuracy is close to that with ordinary Wilson quarks at $M_{\rm PS}/M_{\rm V} \simeq 0.6$ and grows smoothly as $M_{\rm PS}/M_{\rm V}$ decreases.