Charm Physics with Domain Wall Fermions and Physical Pion Masses

TL;DR

This paper reports on lattice QCD calculations of charm meson decay constants using domain wall fermions at physical pion masses, providing preliminary results and strategies for extending to heavier quarks.

Contribution

It introduces a novel approach employing domain wall fermions for charm quarks with physical pion masses, and discusses methods for extrapolating to the continuum and physical heavy quark masses.

Findings

Preliminary decay constants: f_D=208.7(2.8) MeV, f_Ds=246.4(1.9) MeV

Use of domain wall fermions for charm quarks at physical pion masses

Strategies for extending calculations to heavier quark masses

Abstract

We present RBC/UKQCD's charm project using $N_f=2+1$ flavour ensembles with inverse lattice spacings in the range $1.73-2.77\,\mathrm{GeV}$ and two physical pion mass ensembles. Domain wall fermions are used for the light as well as the charm quarks. We discuss our strategy for the extraction of the decay constants $f_D$ and $f_{D_s}$ and their extrapolation to the continuum limit, physical pion masses and the physical heavy quark mass. Our preliminary results are $f_D=208.7(2.8)\,\mathrm{MeV}$ and $f_{D_s}=246.4(1.9)\,\mathrm{MeV}$ where the quoted error is statistical only. We outline our current approach to extend the reach in the heavy quark mass and present preliminary results.