arXiv 1808.028762018-08hep-ph

$B \to D^{*} \barν l$衰变中的螺旋度振幅

Helicity amplitudes in $B \to D^{*} \barν l$ decay

L. R. Dai, E. Oset

备注：: 25 pages, 10 figures
DOI：: 10.1140/epjc/s10052-018-6438-0

摘要：

我们使用最近的弱强子反应的形式主义，映射到强子矩阵元素的夸克水平的过渡矩阵元素，评估与一个精心设计的角动量代数，允许最后写在简单的分析公式的弱矩阵元素。特别是，它们明确地出现在所涉及的矢量介子的不同自旋的第三分量上。我们扩展的形式主义到一般情况下，与运营商$γ^μ-αγ^μγ_5$，可以容纳不同的模型超出标准模型和详细研究的$B \to D^{*} \barν l$反应的不同螺旋的$D^*$。根据每个模型不同的$α$参数显示每个振幅的结果。我们发现，$\frac{d Γ}{d M_{\rm inv}^{(νl)}}$是非常不同的不同组件$M=\pm 1, 0$和特别是幅度$\frac{d Γ}{d M_{\rm inv}^{(νl)}}|_{M=-1} -\frac{d Γ}{d M_{\rm inv}^{(νl)}}|_{M=+1} $是非常敏感的$α$参数，这表明使用这个幅度来测试不同的模型超出了标准模型。我们还将我们的结果与标准模型进行了比较，发现结果非常相似，并且在$M_{\rm inv}^{(νl)}= m_B- m_{D^*}$的终点几乎相同。

英文摘要：

We use a recent formalism of the weak hadronic reactions that maps the transition matrix elements at the quark level into hadronic matrix elements, evaluated with an elaborate angular momentum algebra that allows finally to write the weak matrix elements in terms of easy analytical formulas. In particular they appear explicitly for the different spin third components of the vector mesons involved. We extend the formalism to a general case, with the operator $γ^μ-αγ^μγ_5$, that can accommodate different models beyond the standard model and study in detail the $B \to D^{*} \barν l$ reaction for the different helicities of the $D^*$. The results are shown for each amplitude in terms of the $α$ parameter that is different for each model. We show that $\frac{d Γ}{d M_{\rm inv}^{(νl)}}$ is very different for the different components $M=\pm 1, 0$ and in particular the magnitude $\frac{d Γ}{d M_{\rm inv}^{(νl)}}|_{M=-1} -\frac{d Γ}{d M_{\rm inv}^{(νl)}}|_{M=+1} $ is very sensitive to the $α$ parameter, which suggest to use this magnitude to test different models beyond the standard model. We also compare our results with the standard model and find very similar results, and practically identical at the end point of $M_{\rm inv}^{(νl)}= m_B- m_{D^*}$.

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：

英文摘要：

相关论文