1.0 1.1 1.2 1.3 1.4 1.0 1.1 1.2 1.3 1.4 RBC/UKQCD HPQCD [14] FNAL-MILC [15] f$_{B}$$_{s}$/f$_{B}$$_{d}$ ξ FIG. 9: Comparison of lattice QCD results for f$_{B}$$_{s}$/f$_{B}$$_{d}$ and ξ . The magenta (triangle) denotes our new values obtained by averaging the APE and HYP results, the gray (circle) the values published by the HPQCD Collaboration [14] and the beige (diamond) the preliminary value presented by the FNAL-MILC Collaboration at Lattice 2009 [15]. Computations for this work were carried out in part on facilities of the USQCD Collab- oration, which are funded by the Office of Science of the U.S. Department of Energy. We thank BNL, PPARC, RIKEN, University of Edinburgh, and the U.S. DOE for providing the facilities essential for the completion of this work. The Edinburgh QCDOC system was funded by PPARC JIF grant PPA/J/S/1998/00756 and operated through support from the Universities of Edinburgh, Southampton, and Wales, Swansea and from STFC grant PP/E006965/1. This work was supported in part by the U.S. Department of Energy under grant No. DE-FG02-92ER40699, by Columbia University’s I.I. Rabi grant, by PPARC grants PP/D000238/1 and PP/C503154/1, and by the Grant-in-Aid of the Ministry of Edu- cation, Culture, Sports, Science and Technology, Japan (MEXT Grant), No. 17740138, No. 19740134, and No.21540289. PAB is supported by RCUK. JMF and CTS acknowledge partial support from STFC grant ST/G000557/1 and EU contract MRTN-CT-2006-035482 (Flavianet). This manuscript has been authored by employees of Brookhaven Science Asso- ciates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. RV acknowledges support from BNL via the Goldhaber Distinguished Fellowship. 44