Towards precision charm physics with a mixed action

TL;DR

This paper presents initial results for charm physics using a mixed-action lattice setup with maximally twisted valence fermions, demonstrating promising prospects for high-precision calculations and systematic uncertainty control.

Contribution

It introduces a mixed-action approach with maximally twisted fermions for charm physics, avoiding certain improvement coefficients and enabling continuum and physical pion mass extrapolations.

Findings

Successful computation of charm decay constants on CLS ensembles.

Good scaling properties observed towards the continuum limit.

Potential for high-precision charm physics calculations.

Abstract

We report on our first set of results for charm physics, using a mixed-action setup with maximally twisted valence fermions on CLS $N_f=2+1$ ensembles. This setup avoids the need of improvement coefficients to subtract $O(am_c)$ effects. The charm quark mass, $D$ and $D_s$ decay constants are computed on a subset of CLS ensembles, which allows to take the continuum limit and extrapolate to the physical pion mass, and assess the scaling properties. Special attention is paid to the implementation of techniques to deal with systematic uncertainties. Our results show excellent prospects for high-precision computations on the full set of ensembles.