横动量因子化下自旋不对称度的研究

The spin-related asymmetry appearing in high-energy scattering processes is a powerful tool to probe the spin structure and the flavor dependence of the nucleon. One of the important goals of QCD spin physics is to understand the origins of these spin-related asymmetries. This project employs the transverse momentum dependent factorization and adopts the quark-spectator diquark model under the theoretical field theory and the parameterization to present the calculation of the transverse momentum dependent distributions. With this model results, we study the single and double spin asymmetries of different hadron production in the semi-inclusive deep inelastic scattering, to understand the roles of the quark initial transverse quantum in the high-energy processes. This project focuses on the single or double spins asymmetries at subleading twist of pion production in semi-inclusive deep inelastic scattering, also attempt to study the asymmetries for charged kaon, proton and antiproton production. By comparison with the data of the experimental measurement, we can test the reliability of this theoretical calculation. The future measurements on these asymmetries will test the validity of our predictions, and also shed light on the extraction of the twist-3 transverse momentum dependent distributions.

高能散射过程中出现的与自旋相关的不对称度效应是探索核子内部自旋结构和味道依赖结构的非常有力的工具。理解和探索这些不对称度效应的来源是量子色动力学自旋物理的一个重要目标。本项目将基于横动量因子化框架，采用理论场下的SU (6) 夸克-旁观双夸克模型和参数化的方法对横动量依赖的分布函数的计算，来研究次领头扭度下半单举深度非弹性散射过程不同强子产生中的单自旋和双自旋不对称度，从而考察夸克内禀横动量在高能散射过程中的角色。本项目主要针对半单举深度非弹性散射pion产生过程中的单自旋和双自旋不对称进行探索，同时也对带电kaon，质子、反质子产生过程中的单自旋不对称度进行研究。通过与已有实验测量数据进行对比来检验这套理论计算的可靠性，而未来实验测量数据将会检验我们理论预言的有效性，同时也将在扭度为3的横动量依赖的分布函数的信息提取方面给予启示。