arXiv 0809.08282008-09hep-ex

半轻子衰变$\Bb\to D\ell\nub$和$\Bb\to D^*\ell\nub$的测量--对$D X\ell\nub$末态的整体拟合

Measurements of the Semileptonic Decays $\Bb\to D\ell\nub$ and $\Bb\to D^*\ell\nub$ Using a Global Fit to $D X\ell\nub$ Final States

The BABAR Collaboration, B. Aubert

备注：: 18 pages, 5 figures, submitted to Physical Review D
发表信息：: Phys.Rev.D79:012002,2009
DOI：: 10.1103/PhysRevD.79.012002

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摘要：

半轻子$\bar{B}$衰变为$DX\ell\barν$（$\ell=e$或$mu$）是通过重建$D0\ell$和$D^+\ell$组合来选择的，这些组合来自SLAC PEPII $e^+e^-$对撞机上BaBar探测器记录的2.3亿个$Υ(4S) \to B\bar{B}$衰变样本。在运动学变量的3维空间中对这些样品的全局拟合用于确定分支分数$\mathcal{B}(B^- \to D0\ell\barν) = (2.34 \pm 0.03 \pm 0.13) %$和$\mathcal{B}(B^- \to D^{*0}\ell\barν) = (5.40 \pm 0.02 \pm 0.21) %$，其中误差分别是统计的和系统的。该拟合还确定基于HQET的参数化中的形状因子参数，导致$\bar{B} \to D\ell\barν$的$ρ_D2 = 1.20 \pm 0.04 \pm 0.07$和$\bar{B} \to D^*\ell\barν$的$ρ_{D^*}2 = 1.22 \pm 0.02 \pm 0.07$。这些值用于获得CKM矩阵元素$|V_{cb}|$乘以两种$\bar{B} \to D\ell\barν$衰变的零反冲点处的形状因子$\mathcal{G}(1)|V_{cb}| = (43.1 \pm 0.8 \pm 2.3)\times 10^{-3}$和$\bar{B} \to D^*\ell\barν$衰变的零反冲点处的形状因子$\mathcal{F}(1)|V_{cb}| = (35.9 \pm 0.2 \pm 1.2)\times 10^{-3}$的乘积。

英文摘要：

Semileptonic $\bar{B}$ decays to $DX\ell\barν$ ($\ell=e$ or $mu$) are selected by reconstructing $D0\ell$ and $D^+\ell$ combinations from a sample of 230 million $Υ(4S) \to B\bar{B}$ decays recorded with the BaBar detector at the PEPII $e^+e^-$ collider at SLAC. A global fit to these samples in a 3-dimensional space of kinematic variables is used to determine the branching fractions $\mathcal{B}(B^- \to D0\ell\barν) = (2.34 \pm 0.03 \pm 0.13) %$ and $\mathcal{B}(B^- \to D^{*0}\ell\barν) = (5.40 \pm 0.02 \pm 0.21) %$,where the errors are statistical and systematic, respectively. The fit also determines form factor parameters in a HQET-based parameterization, resulting in $ρ_D2 = 1.20 \pm 0.04 \pm 0.07$ for $\bar{B} \to D\ell\barν$ and $ρ_{D^*}2 = 1.22 \pm 0.02 \pm 0.07$ for $\bar{B} \to D^*\ell\barν$ These values are used to obtain the product of the CKM matrix element $|V_{cb}|$ times the form factor at the zero recoil point for both $\bar{B} \to D\ell\barν$ decays, $\mathcal{G}(1)|V_{cb}| = (43.1 \pm 0.8 \pm 2.3)\times 10^{-3}$, and for $\bar{B} \to D^*\ell\barν$ decays, $\mathcal{F}(1)|V_{cb}| = (35.9 \pm 0.2 \pm 1.2)\times 10^{-3}$.

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。

摘要：

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