Download or read book The Ds and D+ Leptonic Decay Constants from Lattice QCD. written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the leptonic decay constants f{sub D{sub s}} and f{sub D{sup +}} 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 (almost equal to) 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 f{sub D{sub s}} = 260 ± 10 MeV and f{sub D{sup +}} = 217 ± 10 MeV.