The Ds and D+ Leptonic Decay Constants from Lattice QCD

TL;DR

This paper reports lattice QCD calculations of the leptonic decay constants fDs and fD+ using improved methods and multiple lattice spacings, providing updated preliminary results with reduced uncertainties.

Contribution

The study introduces improved analysis techniques, including better discretization effect modeling and retuning of charm quark masses, for more accurate decay constant calculations.

Findings

fDs = 260 +/- 10 MeV

fD+ = 217 +/- 10 MeV

Enhanced analysis methods implemented

Abstract

We present the leptonic decay constants fDs and fD+ computed on the MILC collaboration's 2+1 flavor asqtad gauge ensembles. We use clover heavy quarks with the Fermilab interpretation and improved staggered light quarks. The simultaneous chiral and continuum extrapolation, which determines both decay constants, includes partially-quenched lattice results at lattice spacings a ~ 0:09, 0:12 and 0:15 fm. We have made several recent improvements in our analysis: a) we include terms in the fit describing leading order heavy-quark discretization effects, b) we have adopted a more precise input r1 value consistent with our other D and B meson studies, c) we have retuned the input bare charm masses based upon the new r1. Our preliminary results are fDs = 260 +/-10 MeV and fD+ = 217 +/-10 MeV.