标题： 从Drell-Yan和$J/ψ$产生中限制K介子PDFs 显示英文标题

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

摘要： 由于缺乏介子诱导的Drell-Yan数据，介子部分子分布函数（PDFs）知之甚少。 尽管如此，这些Drell-Yan数据表明，介子中的价$u$夸克分布比介子的更软。 我们讨论利用现有的介子诱导$J/\psi$产生数据来限制介子PDF的可能性。 我们将$K^- / \pi^-$和$K^+ / \pi^+$截面比数据与基于两种全局拟合参数化和两种近期理论预测的计算结果进行比较，并用两种夸克胶子产生模型测试结果。 $K^- / \pi^-$对于$J/\psi$产生的截面比提供了介子和介子中价夸克分布不同的独立证据。 $K^+ / \pi^+$ $J/\psi$ 数据显示出对K介子中的胶子分布敏感。 我们表明这些$J/\psi$生成数据为评估目前可用的K介子PDF集合的充分性提供了有价值的约束。 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 an 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.