PT Journal
AU Bernardoni, F
   Blossier, B
   Bulava, J
   Della Morte, M
   Fritzsch, P
   Garron, N
   Gerardin, A
   Heitger, J
   von Hippel, G
   Simma, H
   Sommer, R
TI Decay constants of B-mesons from non-perturbative HQET with two light dynamical quarks
SO Physics Letters B
JI Phys. Lett. B
PY 2014
BP 349
EP 356
VL 735
DI 10.1016/j.physletb.2014.06.051
LA English
DE Lattice QCD; Heavy Quark Effective Theory; Bottom quarks; Meson decay
AB We present a computation of B-meson decay constants from lattice QCD simulations within the framework of Heavy Quark Effective Theory for the b-quark. The next-to-leading order corrections in the HQET expansion are included non-perturbatively. Based on N-f = 2 gauge field ensembles, covering three lattice spacings a approximate to (0.08-0.05) fm and pion masses down to 190 MeV, a variational method for extracting hadronic matrix elements is used to keep systematic errors under control. In addition we perform a careful autocorrelation analysis in the extrapolation to the continuum and to the physical pion mass limits. Our final results read f(B) = 186(13) MeV, f(Bs) = 224(14) MeV and f(Bs)/f(B) = 1.203(65). A comparison with other results in the literature does not reveal a dependence on the number of dynamical quarks, and effects from truncating HQET appear to be negligible.
ER