arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2607.04481hep-phhep-ex
收藏

专属光子轻子产生测量对质子电荷半径难题的影响

Implications of exclusive photon leptoproduction measurements for the proton charge-radius puzzle

Institute for Research in Fundamental Sciences (IPM)（基础科学研究所）；University of Tehran（德黑兰大学）；Dogus University（多乌斯大学）

The MMGPDs Collaboration, Muhammad Goharipour, Anoushiravan Moradi, K. Azizi

备注：
20 Pages, 7 Figures, and 4 Tables
发表信息：
Phys. Rev.D 114, 074037 (2026)
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

AI总结：

通过纳入CLAS和Hall~A合作组的高精度专属光子轻子产生数据，研究质子电磁形状因子，分析不同数据集一致性，提取电荷和磁半径，发现CLAS 2018测量与其他数据有显著张力，结果支持质子电荷半径难题的小半径解。

摘要：

在本研究中，我们扩展了之前对从专属光子轻子产生（EP）测量中提取的质子电磁形状因子（FFs）的分析，纳入了CLAS和Hall~A合作组所有现有高精度EP数据。使用相同现象学框架，研究不同数据集的一致性，在几种拟合方案中确定质子电磁FFs并提取相应电荷和磁半径。CLAS 2018测量与其余EP数据之间存在显著张力。排除该数据集或通过施加合适的低\(|t|\)切割限制其运动学覆盖范围，会导致具有良好质量和一致FFs的稳定拟合。对于所有分析，提取的质子电荷半径小于粒子数据组平均值和基于弹性电子 - 质子散射的大多数测定值。然而，结果在不确定性范围内与PRad测量和μ子氢光谱一致。相比之下，磁半径与当前世界平均值兼容。这些结果表明，由贝特 - 海特勒（BH）主导的EP测量为确定质子的电磁结构提供了一种独立且互补的方法，并为质子电荷半径难题的小半径解提供了额外支持。

英文摘要：

In the present study, we extend our previous analysis of the proton electromagnetic form factors (FFs) extracted from exclusive photon leptoproduction (EP) measurements in kinematic regions where the Bethe--Heitler (BH) process dominates the cross section by including all currently available high-precision EP data from CLAS and Hall~A Collaborations. Using the same phenomenological framework, we investigate the consistency among the different datasets, determine the proton electromagnetic FFs within several fitting scenarios, and extract the corresponding charge and magnetic radii. A significant tension is found between the CLAS 2018 measurements and the remaining EP data, with the low-$|t|$ region playing a dominant role in this tension. We systematically investigate this behavior through $|t|$-cut scans and assess its impact on the extracted FFs and radii. For all analyses, the extracted proton charge radius is smaller than the Particle Data Group average and most determinations based on elastic electron--proton scattering. However, the results are consistent, within uncertainties, with the PRad measurement and muonic hydrogen spectroscopy. In contrast, the magnetic radius is found to be compatible with the current world average. These results demonstrate that BH-dominated EP measurements provide an independent and complementary approach to determine the electromagnetic structure of the proton and offer additional support for the small-radius solution of the proton charge-radius puzzle.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑