@article{oai:tsukuba.repo.nii.ac.jp:00007808,
 author = {Khan, A. Ali and Aoki, S. and Burkhalter, R. and Ejiri, S. and Fukugita, M. and Hashimoto, S. and Ishizuka, N. and Iwasaki, Y. and 岩崎, 洋一 and Kanaya, K. and Kaneko, T. and Kuramashi, Y. and Manke, T. and Nagai, K. and Okawa, M. and Shanahan, H. P. and Ukawa, A. and 宇川, 彰 and Yoshie, T.},
 issue = {5},
 journal = {Physical review D},
 month = {Aug},
 note = {We present a study of leptonic B meson decay constants in lattice QCD with two flavors (Nf=2) of light dynamical quarks using nonrelativistic QCD for the heavy quark. Gauge configurations are generated with a renormalization-group improved gauge action and a mean-field-improved clover light quark action. Measurements are carried out at two values of β=6/g2, each for four sea quark masses, corresponding to inverse lattice spacings a^-1≈1.3 and 1.8 GeV in the chiral limit of the sea quark. The continuum values of the decay constants are derived by evaluating the discretization errors at each finite lattice spacing. We find fBNf=2=204(8)(29)(+44) MeV, fBsNf=2=242(9)(34)(+38) MeV, and fBsNf=2/fBNf=2=1.179(18)(23), where the errors listed are statistical, systematic and uncertainty due to choice of the physical quantity used to fix the scale. Comparison is made to quenched results (Nf=0) obtained with the same action combination and matching lattice spacings. We find fBNf=2/fBNf=0=1.07(5), fBsNf=2/fBsNf=0=1.10(5) and (fBs/fB)Nf=2/(fBs/fB)Nf=0=1.03(2), which indicate a 5-10 % increase in the values of the decay constants, but no appreciable change in the ratio fBs/fB, due to sea quarks.},
 title = {B meson decay constants from two-flavor lattice QCD with nonrelativistic heavy quarks},
 volume = {64},
 year = {2001}
}