标题： 伪标量介子的电磁和双光子跃迁形式因子：代数模型计算 显示英文标题

标题： Electromagnetic and two-photon transition form factors of the pseudoscalar mesons: An algebraic model computation

摘要： 我们计算基态伪标量介子的电磁和两光子跃迁形式因子：$\pi,\,K,\,\eta_c,\,\eta_b$。 为此，我们采用一种基于施温格-戴森和贝特-萨拉姆方程耦合形式的代数模型。 在该方法中，裸夸克传播子和相关的贝特-萨拉姆振幅包含了相应介子的内部结构。 通过夸克-光子相互作用探测介子的电磁性质。 我们采用的代数模型统一处理所有基态伪标量介子。 其参数经过仔细拟合，进行了对现有实验数据的全局分析，包括对所研究介子电荷半径的知识。 然后，我们计算并预测了广泛范围的探测光子动量平方的电磁和两光子跃迁形式因子，这与迄今为止进行或计划在不同强子物理设施如托马斯·杰斐逊国家加速器设施（JLab）和即将建成的电子-离子对撞机的实验观测直接相关。 我们还与其他理论模型和方法以及格点量子色动力学进行了比较。 显示英文摘要

摘要： We compute electromagnetic and two-photon transition form factors of ground-state pseudoscalar mesons: $\pi,\,K,\,\eta_c,\,\eta_b$. To this end, we employ an algebraic model based upon the coupled formalism of Schwinger-Dyson and Bethe-Salpeter equations. Within this approach, the dressed quark propagator and the relevant Bethe-Salpeter amplitude encode the internal structure of the corresponding meson. Electromagnetic properties of the meson are probed via the quark-photon interaction. The algebraic model employed by us unifies the treatment of all ground-state pseudoscalar mesons. Its parameters are carefully fitted performing a global analysis of existing experimental data including the knowledge of the charge radii of the mesons studied. We then compute and predict electromagnetic and two-photon transition form factors for a wide range of probing photon momentum-squared which is of direct relevance to the experimental observations carried out thus far or planned at different hadron physics facilities such as the Thomas Jefferson National Accelerator Facility (JLab) and the forthcoming Electron-Ion Collider. We also present comparisons with other theoretical models and approaches and lattice quantum chromodynamics.