Charmed pseudoscalar decay constants on three-flavour CLS ensembles with open boundaries

Abstract

We determine the masses and pseudoscalar decay constants of D and $\mathrm{D}_\mathrm{s}$ mesons employing lattice QCD with non-perturbatively ${\cal O}(a)$ improved Wilson quarks and a tree-level Symanzik-improved gauge action. Our analysis is based on the large-volume $\nf=2+1$ ensembles using open boundary conditions, generated within the CLS effort. The status of results presented here covers two lattice spacings, $a\approx 0.0854$ fm and $a\approx 0.0644$ fm, and pion masses varied from 420 to 200 MeV. We also report on our implementation of distance preconditioning for the calculation of heavy quark propagators and discuss the impact of the resulting accuracy improvements on the extraction of charmed meson masses and decay constants. This is part of a continuing analysis by the RQCD and ALPHA Collaborations, aiming at a stable continuum extrapolation using several lattice spacings. To extrapolate to the physical masses, we follow both, the \mbox{$(2\ml+\ms)=\mathrm{const.}$} and the $\ms=\mathrm{const.}$ line in parameter space.