标题： 核子和介子在价夸克区域的分布函数 显示英文标题

标题： Distribution Functions of the Nucleon and Pion in the Valence Region

摘要： 我们从实验和理论的角度探讨了核子和介子在价夸克区域的非极化分布函数的行为；即，Bjorken-x\gtrsim 0.4。 这一区域对于许多强子物理问题至关重要；例如，强子由其味成分定义，而这是价夸克的属性。 此外，对其准确参数化对于提供大型对撞机实验的可靠输入至关重要。 我们关注通过电子和缪子非弹性散射以及Drell-Yan相互作用来提取分布函数的实验方法；以及强调解释分布函数的理论处理，并概述主要的当代方法和问题。 价夸克物理是一个引人入胜的主题，它深入探讨了我们对标准模型理解的核心。 有许多悬而未决的重大挑战，实验和理论必须面对。 在实验方面，我们解释说，升级后的杰弗逊实验室设施非常适合提供核子的新数据，而未来的电子离子对撞机可以为介子提供关键的新数据。 在费米国家加速器实验室、J-PARC和GSI利用Drell-Yan相互作用也具有巨大的潜力，可以将研究推进到介子和核子的大-x区域。 我们进一步认为，与建模和参数化相比，解释需要广泛接受适应理论的必要性：即，从非微扰量子场论的方法中已经学到的经验；以及更充分地利用这些方法。 显示英文摘要

摘要： We provide an experimental and theoretical perspective on the behavior of unpolarized distribution functions for the nucleon and pion on the valence-quark domain; namely, Bjorken-x \gtrsim 0.4. This domain is key to much of hadron physics; e.g., a hadron is defined by its flavor content and that is a valence-quark property. Furthermore, its accurate parametrization is crucial to the provision of reliable input for large collider experiments. We focus on experimental extractions of distribution functions via electron and muon inelastic scattering, and from Drell-Yan interactions; and on theoretical treatments that emphasize an explanation of the distribution functions, providing an overview of major contemporary approaches and issues. Valence-quark physics is a compelling subject, which probes at the heart of our understanding of the Standard Model. There are numerous outstanding and unresolved challenges, which experiment and theory must confront. In connection with experiment, we explain that an upgraded Jefferson Lab facility is well-suited to provide new data on the nucleon, while a future electron ion collider could provide essential new data for the mesons. There is also great potential in using Drell-Yan interactions, at FNAL, J-PARC and GSI, to push into the large-x domain for both mesons and nucleons. We argue furthermore that explanation, in contrast to modeling and parametrization, requires a widespread acceptance of the need to adapt theory: to the lessons learnt already from the methods of nonperturbative quantum field theory; and a fuller exploitation of those methods.