Simulating twisted mass fermions at physical light, strange and charm quark masses

TL;DR

This paper reports on the first physical-point QCD simulation using twisted mass fermions with light, strange, and charm quarks, confirming the ensemble's physical accuracy through various hadronic observables.

Contribution

It introduces a novel gauge ensemble with all quark masses tuned to their physical values using twisted mass fermions, including a detailed analysis of systematic effects.

Findings

Pseudoscalar masses and decay constants match experimental values.

Cutoff and isospin breaking effects are minimized with a clover term.

The ensemble accurately reproduces baryon sector observables.

Abstract

We present the QCD simulation of the first gauge ensemble of two degenerate light quarks, a strange and a charm quark with all quark masses tuned to their physical values within the twisted mass fermion formulation. Results for the pseudoscalar masses and decay constants confirm that the produced ensemble is indeed at the physical parameters of the theory. This conclusion is corroborated by a complementary analysis in the baryon sector. We examine cutoff and isospin breaking effects and demonstrate that they are suppressed through the presence of a clover term in the action.