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arXiv 0811.3640hep-lathep-ph
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三味格点量子色动力学的B -> pi l nu半轻子形状因子:与模型无关的确定|V(ub)|

The B -> pi l nu semileptonic form factor from three-flavor lattice QCD: A model-independent determination of |V(ub)|

Jon A. Bailey, C. Bernard, C. DeTar, M. Di Pierro, A. X. El-Khadra, R. T. Evans, E. D. Freeland, E. Gamiz, Steven Gottlieb, U. M. Heller, J. E. Hetrick, A. S. K… 展开作者

Jon A. Bailey, C. Bernard, C. DeTar, M. Di Pierro, A. X. El-Khadra, R. T. Evans, E. D. Freeland, E. Gamiz, Steven Gottlieb, U. M. Heller, J. E. Hetrick, A. S. Kronfeld, J. Laiho, L. Levkova, P. B. Mackenzie, M. Okamoto, J. N. Simone, R. Sugar, D. Toussaint, R. S. Van de Water

摘要:

本文计算了含2+1味轻海夸克的非猝灭格点量子色动力学中B介子半轻子衰变的形状因子f+(q^2)。我们使用Asqtad改进的交错轻夸克和费米实验室底夸克的规范配置产生的MILC合作。我们模拟了几种轻夸克质量和两种晶格间距,并利用重-轻介子交错手征微扰理论外推到物理夸克质量和连续极限。然后,我们使用仅依赖于解析性和么正性的q^2中的形状因子形状的参数化来确定CKM矩阵元,同时拟合f+(q^2)的晶格结果和BABAR实验测量的晶格结果|V(ub)|.这种方法减少了总的不确定性,|V(ub)|通过以最佳的、与模型无关的方式组合晶格和实验信息。我们找到一个值|V(ub)|x 10^3 = 3.38 +/- 0.36。

英文摘要:

We calculate the form factor f_+(q^2) for B-meson semileptonic decay in unquenched lattice QCD with 2+1 flavors of light sea quarks. We use Asqtad-improved staggered light quarks and a Fermilab bottom quark on gauge configurations generated by the MILC Collaboration. We simulate with several light quark masses and at two lattice spacings, and extrapolate to the physical quark mass and continuum limit using heavy-light meson staggered chiral perturbation theory. We then fit the lattice result for f_+(q^2) simultaneously with that measured by the BABAR experiment using a parameterization of the form factor shape in q^2 which relies only on analyticity and unitarity in order to determine the CKM matrix element |V(ub)|. This approach reduces the total uncertainty in |V(ub)| by combining the lattice and experimental information in an optimal, model-independent manner. We find a value of |V(ub)| x 10^3 = 3.38 +/- 0.36.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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