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arXiv 0807.2944hep-lathep-ex
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矢量通道B --> D* l nu衰变率的猝灭晶格计算

Quenched lattice calculation of the vector channel B --> D* l nu decay rate

G. M. de Divitiis, R. Petronzio, N. Tantalo

摘要:

在猝灭格点量子色动力学的连续极限下,我们计算了进入半轻子衰变B --> D* lnu的形状因子.本文利用以前处理格点量子色动力学中两个标度问题的阶梯标度法(SSM),采用味扭曲边界条件,求出了有限动量转移和重夸克质量物理值下的F(w)。我们的结果可以用来提取CKM矩阵元Vcb的实验衰减率没有依赖于模型的外推。Vcb的值与从B -> Dlnu通道获得的值一致,并且使我们确信猝灭近似很好地适用于这些跃迁。

英文摘要:

We calculate, in the continuum limit of quenched lattice QCD, the form factor that enters the decay rate of the semileptonic decay B --> D* l nu. By using the step scaling method (SSM), previously introduced to handle two scale problems in lattice QCD, and by adopting flavor twisted boundary conditions we extract F(w) at finite momentum transfer and at the physical values of the heavy quark masses. Our results can be used in order to extract the CKM matrix element Vcb by the experimental decay rate without model dependent extrapolations. The value of Vcb agrees with the one obtained from the B --> D l nu channel and makes us confident that the quenched approximation well applies to these transitions.

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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