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arXiv 0910.3534hep-ex
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衰变B^+ \to \bar D^{*0} \ell^+ v_ \ell的形状因子的测量和CKM矩阵元素的确定|V_{cb}|

Measurement of the form factors of the decay B^+\to\bar D^{*0}\ell^+ν_\ell and determination of the CKM matrix element |V_{cb}|

The Belle Collaboration

摘要:

我们提出了一个测量的Cabibbo-小林-Maskawa矩阵元素$|V_{cb}|$倍的形状因子归一化$\mathcal{F}(1)$使用的衰减$B^+\to\bar D^{*0}\ell^+ν_\ell$。这种测量是一起进行的形状因子参数$ρ^2$,$R_1(1)$和$R_2(1)$,充分表征这种衰变的框架中的重夸克有效理论的确定。该分析基于在$Υ(4S)$共振附近收集的相当于Belle数据的140 fb $^{-1}$的数据样本。基于大约27,000个重建的$B^+\to\bar D^{*0}\ell^+ν_\ell$衰变,初步结果是$ρ^2=1.376\pm 0.074\pm 0.056$,$R_1(1)=1.620\pm 0.091\pm 0.092$,$R_2(1)=0.805\pm 0.064\pm 0.036$和$\mathcal{F}(1)|V_{cb}|=35.0\pm 0.4\pm 2.2$。我们发现$B^+\to\bar D^{*0}\ell^+ν_\ell$分支分数是$(4.84\pm 0.04\pm 0.56)%$。对于这里引用的所有数字,第一个误差是统计误差,第二个误差是系统不确定性。还进行了形状因子形状的直接的、与模型无关的确定,并且显示出与Caprini { \it等人}的基于HQET的形状因子参数化的良好一致性。

英文摘要:

We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ times the form factor normalization $\mathcal{F}(1)$ using the decay $B^+\to\bar D^{*0}\ell^+ν_\ell$. This measurement is performed together with a determination of the form factor parameters $ρ^2$, $R_1(1)$ and $R_2(1)$ which fully characterize this decay in the framework of Heavy Quark Effective Theory. This analysis is based on a data sample equivalent to 140 fb$^{-1}$ of Belle data collected near the $Υ(4S)$ resonance. The preliminary results, based on about 27,000 reconstructed $B^+\to\bar D^{*0}\ell^+ν_\ell$ decays, are $ρ^2=1.376\pm 0.074\pm 0.056$, $R_1(1)=1.620\pm 0.091\pm 0.092$, $R_2(1)=0.805\pm 0.064\pm 0.036$ and $\mathcal{F}(1)|V_{cb}|=35.0\pm 0.4\pm 2.2$. We find the $B^+\to\bar D^{*0}\ell^+ν_\ell$ branching fraction to be $(4.84\pm 0.04\pm 0.56)%$. For all numbers quoted here, the first error is the statistical and the second is the systematic uncertainty. A direct, model-independent determination of the form factor shapes has also been carried out and shows good agreement with the HQET based form factor parametrization by Caprini {\it et al.}.

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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