Experimental measurements in deep-inelastic scattering and lepton-pair production on deuterium targets play an important role in the flavor separation of u and d (anti)quarks in global QCD analyses of the parton distribution functions (PDFs) of the nucleon. We investigate the impact of theoretical corrections accounting for the light-nuclear structure of the deuteron upon the fitted u, d-quark, gluon, and other PDFs in the CJ15 and CT18 families of next-to-leading order CTEQ global analyses. The investigation is done using the \(L_2\) sensitivity statistical method, which provides a common metric to quantify the strength of experimental constraints on various PDFs and ratios of PDFs in the two distinct fitting frameworks. Using the \(L_2\) sensitivity and other approaches, we examine the compatibility of deuteron data sets with other fitted experiments under varied implementations of the deuteron corrections. We find that freely-fitted deuteron corrections modify the PDF uncertainty at large momentum fractions and will be relevant for future PDFs affecting electroweak precision measurements.

氘靶上的深非弹性散射和轻子对产生的实验测量在核子部分子分布函数 (PDF) 的全局 QCD 分析中u和d（反）夸克的风味分离中起着重要作用。我们研究了解释氘核轻核结构的理论修正对 CJ15 和 CT18 家族次先序 CTEQ 全局分析中拟合的u、  d夸克、胶子和其他 PDF 的影响。调查是使用\(L_2\)灵敏度统计方法，它提供了一个通用指标来量化对各种 PDF 的实验约束的强度和两个不同拟合框架中 PDF 的比率。使用\(L_2\)灵敏度和其他方法，我们检查了氘核数据集在不同的氘核校正实现下与其他拟合实验的兼容性。我们发现自由拟合的氘核修正修改了大动量分数的 PDF 不确定性，并将与影响电弱精度测量的未来 PDF 相关。