The D-meson leading-twist distribution amplitude (DA) is an universal physical quantity for applying QCD light-cone sum rules or perturbative QCD method to exclusive processes involving D-meson. Although several models have been used in the literature, we do not have enough knowledge to determine it. Inversely, one expects that the D-meson DA can be constrained in principle by the processes containing D-meson. In this paper, we try to extract the information of D-meson DA’s behavior from the experimental data of B → D semi-leptonic decay. A revised light-cone harmonic oscillator model has been suggested. It can mimic most of the suggested D-meson DA behaviors, whose parameters can be fixed by the constraints from the processes involving D-meson. By combining the D-meson decay channel $D\to \mu \bar {\nu }$ , the semi-leptonic decay $B\to Dl\bar {\nu }_{l}$ and the constrain that the probability of finding the leading Fock-state $|\bar {c}q>$ in the D-meson Fock state expansion, we restrict the parameter BD in our DA model as BD ∈ [0.00, 0.23]. In order to improve the complexity of the evolution of the oscillator model, we give the fitting formulas for the evolution of the model parameters. Then we calculate the branching ratios ${\mathscr{B}}(\overline {B}^{0}\to D^{+}l\nu _{l})$ and ${\mathscr{B}}(B^{-}\to D^{0}l\bar {\nu }_{l})$ , which agree with the experimental data.

中文翻译：

---

D 介子引导扭曲分布幅度从 $B\到 Dl\bar {\nu }_{l}$ 半轻子衰变

D-介子引导扭曲分布幅度 (DA) 是一个通用物理量，用于将 QCD 光锥和规则或微扰 QCD 方法应用于涉及 D-介子的排他过程。尽管文献中使用了几种模型，但我们没有足够的知识来确定它。相反，人们期望 D-介子 DA 原则上可以受到包含 D-介子的过程的约束。在本文中，我们尝试从 B → D 半轻子衰变的实验数据中提取 D-介子 DA 的行为信息。已提出修正的光锥谐振子模型。它可以模仿大多数建议的 D-介子 DA 行为，其参数可以通过涉及 D-介子的过程的约束来固定。通过结合 D-介子衰变通道 $D\to \mu \bar {\nu }$ ，半轻子衰变 $B\to Dl\bar {\nu }_{l}$ 以及在 D 介子 Fock 中找到领先 Fock 状态的概率 $|\bar {c}q>$ 的约束状态扩展，我们将 DA 模型中的参数 BD 限制为 BD ∈ [0.00, 0.23]。为了提高振子模型演化的复杂度，我们给出了模型参数演化的拟合公式。然后我们计算分支比 ${\mathscr{B}}(\overline {B}^{0}\to D^{+}l\nu _{l})$ 和 ${\mathscr{B}}( B^{-}\to D^{0}l\bar {\nu }_{l})$ ，与实验数据一致。我们给出了模型参数演化的拟合公式。然后我们计算分支比 ${\mathscr{B}}(\overline {B}^{0}\to D^{+}l\nu _{l})$ 和 ${\mathscr{B}}( B^{-}\to D^{0}l\bar {\nu }_{l})$ ，与实验数据一致。我们给出了模型参数演化的拟合公式。然后我们计算分支比 ${\mathscr{B}}(\overline {B}^{0}\to D^{+}l\nu _{l})$ 和 ${\mathscr{B}}( B^{-}\to D^{0}l\bar {\nu }_{l})$ ，与实验数据一致。