B-meson decay constants from improved lattice nonrelativistic QCD with physical u, d, s, and c quarks.
B-meson decay constants from improved lattice nonrelativistic QCD with physical u, d, s, and c quarks.
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DOI：
10.1103/physrevlett.110.222003
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发表时间：
2013-05
影响因子：
8.6
通讯作者：
R. Dowdall;C. Davies;R. Horgan;C. Monahan;J. Shigemitsu
中科院分区：
文献类型：
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作者：
R. Dowdall;C. Davies;R. Horgan;C. Monahan;J. Shigemitsu
本文首次用格点QCD方法计算了具有物理轻夸克质量的衰变常数f（B）和f（B（s））。我们使用由MILC协作产生的配置，包括在三个晶格间距和三个u/d夸克质量值下降到物理值的海中的u，d，s和c高度改进的交错夸克的效果。对于价B夸克，我们采用改进的非相对论QCD（NRQCD）。我们的结果是：f（B）=0.186（4）GeV，f（B（s））=0.224（4）GeV，f（B（s））/f（B）=1.205（7），M（B（s））-M（B）=85（2）MeV，取代了NRQCD B夸克的早期结果.我们讨论了我们的结果对标准模型速率B（（s））→μ（+）μ（-）和B→τν的意义.
We present the first lattice QCD calculation of the decay constants f(B) and f(B(s)) with physical light quark masses. We use configurations generated by the MILC Collaboration including the effect of u, d, s, and c highly improved staggered quarks in the sea at three lattice spacings and with three u/d quark mass values going down to the physical value. We use improved nonrelativistic QCD (NRQCD) for the valence b quarks. Our results are f(B)=0.186(4) GeV, f(B(s))=0.224(4) GeV, f(B(s))/f(B)=1.205(7), and M(B(s))-M(B)=85(2) MeV, superseding earlier results with NRQCD b quarks. We discuss the implications of our results for the standard model rates for B((s))→μ(+)μ(-) and B→τν.