标题： 从Drell-Yan和$J/ψ$产生约束 kaon部分子分布函数 显示英文标题

标题： Constraining kaon PDFs from Drell-Yan and $J/ψ$ production

摘要： 由于由K介子诱导的Drell-Yan数据匮乏，K介子的部分子分布函数（PDFs）知之甚少。然而，这些Drell-Yan数据表明K介子的价态$u$夸克分布比π介子的更软。我们讨论了利用现有的K介子诱导的$J/\psi$生产数据来限制K介子PDFs的机会。我们将$K^- / \pi^-$和$K^+ / \pi^+$的横截面比率数据与基于两种全局拟合参数化方法以及两种最近的理论预测（针对K介子和π介子的PDFs）的计算结果进行了比较，并用两种夸克偶素生产模型检验了这些结果。对于$J/\psi$生产的$K^- / \pi^-$横截面比率提供了π介子和K介子中价态夸克分布不同的独立证据。 发现$K^+ / \pi^+$ $J/\psi$ 数据对 kaon 中的胶子分布敏感。我们表明这些$J/\psi$生产数据为评估目前可用的 kaon PDF 集合的适用性提供了宝贵的约束条件。 显示英文摘要

摘要： The kaon parton distribution functions (PDFs) are poorly known due to paucity of kaon-induced Drell-Yan data. Nevertheless, these Drell-Yan data suggest a softer valence $u$ quark distribution of kaon than that of pion. We discuss the opportunity to constrain kaon PDFs utilizing existing kaon-induced $J/\psi$ production data. We compare the $K^- / \pi^-$ and $K^+ / \pi^+$ cross-section ratio data with calculations based on two global-fit parametrizations and two recent theoretical predictions for the kaon and pion PDFs, and test the results with two quarkonium production models. The $K^- / \pi^-$ cross-section ratio for $J/\psi$ production provides independent evidence of different valence quark distributions in pion and kaon. The $K^+ / \pi^+$ $J/\psi$ data are found to be sensitive to the gluon distribution in kaon. We show that these $J/\psi$ production data provide valuable constraints for evaluating the adequacy of currently available sets of kaon PDFs.