Dynamical Twisted Mass Fermions with Light Quarks

TL;DR

This paper reports on dynamical lattice QCD simulations using twisted mass fermions with light quarks, achieving precise measurements of pseudoscalar properties and comparing results with chiral perturbation theory.

Contribution

The study demonstrates the effectiveness of twisted mass fermions at maximal twist for simulating light quarks with small residual cutoff effects and provides precise low energy constants.

Findings

Accurate pseudoscalar decay constants and masses obtained.

Results agree well with chiral perturbation theory predictions.

Low energy constants F, _3, and _4 determined with small errors.

Abstract

We present results of dynamical simulations with 2 flavours of degenerate Wilson twisted mass quarks at maximal twist in the range of pseudo scalar masses from 300 to 550 MeV. The simulations are performed at one value of the lattice spacing a \lesssim 0.1 fm. In order to have O(a) improvement and aiming at small residual cutoff effects, the theory is tuned to maximal twist by requiring the vanishing of the untwisted quark mass. Precise results for the pseudo scalar decay constant and the pseudo scalar mass are confronted with chiral perturbation theory predictions and the low energy constants F, \bar{l}_3 and \bar{l}_4 are evaluated with small statistical errors.