Consistent treatment for pion form factors in spacelike and timelike regions
Consistent treatment for pion form factors in spacelike and timelike regions
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DOI：
10.1103/physrevd.64.034011
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发表时间：
2001-05
影响因子：
5
通讯作者：
C. Hwang
中科院分区：
文献类型：
--
作者：
C. Hwang
通过考虑夸克-介子顶点函数，我们写出了π介子散射和衰变过程的一些相关矩阵元。π电荷和跃迁形状因子$F_\pi$，$F_{\pi\gamma}$和$F_{\pi\gamma^*}$从这些矩阵元素中提取使用相对论夸克模型的光阵面。我们发现，类空区的形状因子F_\pi$和F_{\pi\gamma}$与实验符合得很好。此外，在类时区域内所观测到的与形状因子F_{\pi\gamma}$和F_{\pi\gamma^*}$有关的中性π介子衰变模的分支比也与实验数据一致。此外，还讨论了类时区域中的F\pi，它涉及非价贡献。
We write down some relevant matrix elements for the scattering and decay processes of the pion by considering a quark-meson vertex function. The pion charge and transition form factors $F_\pi$, $F_{\pi\gamma}$, and $F_{\pi\gamma^*}$ are extracted from these matrix elements using a relativistic quark model on the light-front. We found that, the form factors $F_\pi$ and $F_{\pi\gamma}$ in the space-like region agree well with experiment. Furthermore, the branching ratios of all observed decay modes of the neutral pion, that are related to the form factors $F_{\pi\gamma}$ and $F_{\pi\gamma^*}$ in the time-like region, are all consistent with the data as well. Additionally, $F_\pi$ in the time-like region, which deals with the nonvalence contribution, is also discussed.