发表机构
Forschungszentrum Jülich; Universität Bonn; Beihang University（于利希研究中心; 波恩大学; 北京航空航天大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究扩展Gari-Krümpelmann模型，在同位旋矢量道显式纳入色散双π连续谱，用5个参数清晰分离三类动力学，成功描述类空区域核子电磁形状因子及电子-质子散射微分截面数据。
AI 中文摘要
Gari-Krümpelmann（GK）模型是首批在宽动量转移范围内对半经验性描述核子电磁形状因子的模型之一，它结合了低和中等动量转移下的矢量介子主导理论，以及大动量转移下的微扰量子色动力学（pQCD）约束。本研究通过在同位旋矢量道中显式纳入色散双π连续谱，扩展了该框架；双π贡献取自现代色散分析，并嵌入到GK假设的固有高Q²结构中，随后将物理ρ动力学解释为关联双π谱函数的一部分，而直接耦合项对于向渐近区的过渡仍至关重要。这实现了长程连续谱动力学、相干矢量介子贡献与直接夸克流动力学之间更清晰的分离。仅用5个参数，即可描述大量类空区域内的形状因子数据及电子-质子散射的微分截面。
英文摘要
The Gari--Krümpelmann (GK) model provided one of the first semiphenomenological descriptions of the electromagnetic nucleon form-factors over a wide range of momentum transfer. It combined vector-meson dominance at low and intermediate momentum transfer with perturbative-QCD constraints at large momentum transfer. The present work extends this framework by including the dispersive two-pion continuum explicitly in the isovector channel. The two-pion contribution is taken from modern dispersive analyses and embedded into the intrinsic high-$Q^2$ structure of the GK ansatz. The physical $ρ$ dynamics is then interpreted as part of the correlated two-pion spectral function. Similarly, we include in the isoscalar spectral function the correlated $K\bar K$ and $ρπ$ continua, where the former also includes the $ϕ$-meson pole. The direct coupling terms remain essential for the transition to the asymptotic regime. This gives a cleaner separation between long-range continuum dynamics, coherent vector-meson contributions, and direct quark-current dynamics. With just 7 parameters, we can describe the large body on form-factor data and differential cross sections from electron-proton scattering in the space-like region.
Comments13 pages, 4 figures, improved version including also the isoscalar continua
