AI 中文总结
研究标量粲介子\(D_0^*(2300)\)双极点结构，用有效拉格朗日方法计算其衰变常数，所得值小于传统预测，表明衰变常数可区分其内部结构，还预测了相关衰变分支比，为双极点解释提供关键检验。
AI 中文摘要
标量粲介子\(D_0^*(2300)\)的性质仍是强子谱学中最引人入胜的状态之一。一种主流解释是由耦合通道\(D\pi\)、\(D\eta\)、\(D_s\bar K\)和\(D\eta'\)产生的双极点结构，其中较低极点主要耦合到\(D\pi\)，较高极点耦合到\(D_s\bar K\)。我们用有效拉格朗日方法计算这两个极点的衰变常数，结果值\(f_{D_0^*}^{(\mathrm{lower})}=64.6^{+0.9}_{-1.0}\,\mathrm{MeV}\)和\(f_{D_0^*}^{(\mathrm{higher})}=80.8^{+9.6}_{-5.3}\,\mathrm{MeV}\)，远小于传统\(c\bar q\)激发态情形的预测值。这种差异表明衰变常数可作为区分\(D_0^*(2300)\)不同内部结构的灵敏探针。作为唯象学应用，我们在因子化方法内进一步预测了Cabibbo允许衰变\(B_s \to D_s D_0^*\)、\(\Lambda_b \to \Lambda_c D_0^*\)和\(\Xi_b \to \Xi_c D_0^*\)的分支比。这些预测为验证\(D_0^*(2300)\)的双极点解释提供了关键检验。
英文摘要
The nature of the scalar charmed meson $D_0^*(2300)$ remains one of the most intriguing states in hadron spectroscopy. A prominent interpretation is a two-pole structure generated by the coupled channels $Dπ$, $Dη$, $D_s\bar K$, and $Dη'$, in which the lower pole couples mainly to $Dπ$ and the higher pole to $D_s\bar K$. Following this picture, we calculate the decay constants of these two poles using the effective Lagrangian approach. The resulting values, $f_{D_0^*}^{(\mathrm{lower})}=64.6^{+0.9}_{-1.0}\,\mathrm{MeV}$ and $f_{D_0^*}^{(\mathrm{higher})}=80.8^{+9.6}_{-5.3}\,\mathrm{MeV}$, are substantially smaller than those predicted by conventional $c\bar q$ excited-state scenarios. This difference suggests that decay constants can serve as a sensitive probe to discriminate between different internal structures of the $D_0^*(2300)$. As a phenomenological application, we further predict the branching fractions for the Cabibbo-favored decays $B_s \to D_s D_0^*$, $Λ_b \to Λ_c D_0^*$, and $Ξ_b \to Ξ_c D_0^*$ within the factorization approach. These predictions provide crucial tests to validate the two-pole interpretation of the $D_0^*(2300)$.
