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arXiv · 1309.4610

B, Bs, K and pi weak matrix elements with physical light quarks

R. J. Dowdall·C. T. H. Davies·R. R. Horgan·G. P. Lepage·C. McNeile·C. J. Monahan·J. Shigemitsu
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Abstract

Calculations of pseudoscalar decay constants of B, Bs, K and pi mesons with physical light quarks are presented. We use HISQ ensembles that include u,d,s and c sea quarks at three lattice spacings. HISQ is used for the valence light quarks and a radiatively improved NRQCD action for the heavy quarks. The key results are f_{B^+}=0.184(4)$ GeV, f_{B_s}=0.224(4) GeV, f_{B_s}/f_{B^+}=1.217(8), f_{K^+}/f_{pi^+}=1.1916(21), f_{K^+}=155.37(34) MeV, giving a significant improvement over previous results that required chiral extrapolation. We also calculate the Wilson flow scale w_0, finding w_0=0.1715(9) fm.

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R. J. Dowdall, C. T. H. Davies, R. R. Horgan, G. P. Lepage, C. McNeile, C. J. Monahan, J. Shigemitsu. 2013-09-18. B, Bs, K and pi weak matrix elements with physical light quarks. https://arxiv.org/abs/1309.4610

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