We present the first lattice QCD calculation with realistic sea quark content of the D^+ meson decay constant f_{D^+}. We use the MILC Collaboration's publicly available ensembles of lattice gauge fields, which have a quark sea with two flavors (up and down) much lighter than a third (strange). We obtain f_{D^+} = 201 +/- 3 +/- 17 MeV, where the errors are statistical and a combination of systematic errors. We also obtain f_{D_s} = 249 +/- 3 +/- 16 MeV for the D_s meson.
@article{arxiv.hep-lat/0506030,
title = {Charmed meson decay constants in three-flavor lattice QCD},
author = {C. Aubin and C. Bernard and C. DeTar and M. Di Pierro and E. D. Freeland and Steven Gottlieb and U. M. Heller and J. E. Hetrick and A. X. El-Khadra and A. S. Kronfeld and L. Levkova and P. B. Mackenzie and D. Menscher and F. Maresca and M. Nobes and M. Okamoto and D. Renner and J. Simone and R. Sugar and D. Toussaint and H. D. Trottier},
journal= {arXiv preprint arXiv:hep-lat/0506030},
year = {2008}
}
Comments
note added on recent CLEO measurement; PRL version