核子自旋结构的实验研究进展

Progress in experimental studies on longitudinal spin structure of nucleon

本文主要介绍对核子纵向自旋结构函数的实验研究进展。首先简要介绍核子自旋结构的部分理论模型,包括朴素的部份子模型和QCD中的夸克–部份子模型,同时简要介绍标度律和标度律的破坏及其原因;接着介绍实验研究的理论基础,包括弱作用和轻子–核子的深度非弹散射中轴流的作用和几个关于核子自旋结构的求和规则和它们的QCD修正;且简要介绍深度非弹散射实验的研究方法,包括单举测量、半单举和遍举测量。最后,详细介绍实验研究进展,包括对质子和中子的纵向自旋结构函数的测量,国际上几个主要实验室在不同的能量下,在用不同的靶、不同的束流对不同范围的Bjorken变量x和不同的四动量转移范围Q2下的实验、特点及其结果。最后简略介绍了我国实验物理工作者在该领域的国际合作组的部分工作。

This paper presents the progress on the study of the longitudinal spin structure functions of nucleon. First, we describe a few theories on spin structure, including naive parton model and the quark-parton model in the QCD. At same time, we introduce the scaling rule and the reason of its violation. The basic theories for the experimental study are then explained, including the roles of axis currents in the weak interaction and deep inelastic scattering of lepton-nucleon, and several sum rules of spin structure function of nucleon and their QCD correction. Second, we discuss the experimental methods on measurement of cross sections asymmetry in the deep inelastic scattering（DIS）, including inclusive, semi-inclusive, and exclusive measurements. At last, various kinds of experimental studies and their characteristics from major laboratories around the world and their results in the last forty years are described in details in this article.