标题： 亮点与杰弗逊实验室自旋物理计划的展望 显示英文标题

标题： Highlights and Perspectives of the JLab Spin Physics Program

摘要： 核子自旋结构在过去三十年一直是备受关注和令人兴奋的研究领域。 最近杰弗逊实验室的精确自旋结构数据显著推进了我们在价夸克（高x）区域对核子结构的认识，并改善了我们对高扭曲效应、自旋求和规则和夸克-强子二象性的理解。 首先，介绍了低到中等Q^2区域的自旋求和规则和极化率的结果。 讨论了与理论计算的比较。 发现手征微扰理论计算与实验结果在广义自旋极化率\delta _{LT}方面存在令人惊讶的不一致。 然后，介绍了高x区域自旋不对称性的精确测量结果。 这些结果为全球数据拟合提供了关键输入，以提取极化部分子分布函数。 提取了核子中上夸克和下夸克的自旋分布。 对于\Delta d/d的结果与假设强子螺旋度守恒的领先阶pQCD预测不一致。 介绍了用于研究高扭曲效应的g_2结构函数的精确测量结果。 数据表明存在显著的高扭曲（扭3或更高）效应。 提取了自旋结构函数的二阶矩和扭3矩阵元d_2的结果。 将高Q^2结果与格点QCD计算进行了比较。 介绍了中等Q^2范围内的共振自旋结构函数的结果，这些结果结合DIS数据，使得能够详细研究自旋结构函数中的夸克-强子二象性。 最后，讨论了一项研究中子横向自旋和横向自旋不对称性的实验。 简要概述了JLab 12 GeV能量升级的未来计划。 显示英文摘要

摘要： Nucleon spin structure has been an active and exciting subject of interest for the last three decades. Recent precision spin-structure data from Jefferson Lab have significantly advanced our knowledge of nucleon structure in the valence quark (high-x) region and improved our understanding of higher-twist effects, spin sum rules and quark-hadron duality. First, results of spin sum rules and polarizabilities in the low to intermediate Q^2 region are presented. Comparison with theoretical calculations are discussed. Surprising disagreements of Chiral Perturbation Theory calculations with experimental results on the generalized spin polarizability, \delta_{LT}, were found. Then, precision measurements of the spin asymmetry in the high-x region are presented. They provide crucial input for global fits to world data to extract polarized parton distribution functions. The up and down quark spin distributions in the nucleon were extracted. The results for \Delta d/d disagree with the leading-order pQCD prediction assuming hadron helicity conservation. Results of precision measurements of the g_2 structure function to study higher-twist effects are presented. The data indicate a significant higher-twist (twist-3 or higher) effect. The second moment of the spin structure functions and the twist-3 matrix element d_2 results were extracted. The high Q^2 result was compared with a Lattice QCD calculation. Results on the resonance spin-structure functions in the intermediate Q^2 range are presented, which, in combination with DIS data, enable a detailed study of quark-hadron duality in spin-structure functions. Finally, an experiment to study neutron transversity and transverse spin asymmetries is discussed. A future plan with the 12 GeV energy upgrade at JLab is briefly outlined.