中高横动量区域内高能散射过程中物理可观测量的研究

One of the goals of transverse momentum dependent (TMD) factorization theorem is to describe the physical observables as the function of the transverse momentum q_T point by point in the whole region of transverse momentum. Based on the TMD factorization theorem, the cross section of high energy scattering processes can be expressed by the W+Y prescription. The W-term is an approximation in small q_T region (q_T<<Q), which dominates at small limit of q_T/Q, and involves TMD parton distribution functions (PDF) and fragmentation functions (FF). The Y-term serves as the correction for mediate and large q_T values (q_T~Q) and involves the collinear PDF and FF. It was shown that perturbative correction from the Y-term may play an important role in the q_T~Q region. Thus, considering both the contributions from W-term and Y-term, further study on the qualitative and quantitative analysis of the physical observables in high energy scattering processes in mediate and large q_T region is needed in order to provide a complete picture and accurate prediction of the physical observables in the whole q_T range. In the framework of the TMD factorization, taking into account both the TMD evolution effects of the TMD PDF/FF in the W-term and the necessary correction Y-term in the mediate and large q_T region, we will further study the physical observables related to the transverse polarization in high energy processes. It will deepen our understanding of the QCD dynamics and the internal structure of hadrons, also be helpful to verify the validity of the factorization theorems.

横动量依赖(TMD)因子化定理的目标之一是在尽可能广的横动量区域内将物理可观测量作为横动量q_T的函数进行逐点描述。基于TMD因子化定理，高能散射过程的微分散射截面可写成W+Y的形式：W是小横动量近似下(q_T<<Q,Q为过程能标)关于TMD分布函数和碎裂函数的项，在q_T/Q较小时占据主导地位；Y是在中高横动量区域(q_T~Q)与共线分布函数和碎裂函数相关的修正项。研究表明在中高横动量区域修正项Y可能起着重要作用，因此，同时考虑W项和Y项对高能散射过程的物理可观测量进行定性、定量分析，这对研究整个横动量区域的物理可观测量是十分必要的。本项目拟在中高横动量区域TMD因子化框架下，考虑W项中TMD分布函数和碎裂函数的演化效应及修正项Y，对高能散射过程中横极化相关的物理可观测量进行进一步的研究，这将加深我们对QCD动力学和强子内部结构的理解，同时检验因子化定理的有效性。

横动量依赖(TMD)因子化定理的目标之一是在尽可能广的横动量区域内将物理可观测量作为横动量q_T的函数进行逐点描述。基于TMD因子化定理，高能散射过程的微分散射截面可写成W+Y的形式：W是小横动量近似下(q_T<<Q,Q为过程能标)关于TMD分布函数和碎裂函数的项，在q_T/Q较小时占据主导地位；Y是在中高横动量区域(q_T~Q)与共线分布函数和碎裂函数相关的修正项。本项目在TMD因子化框架下，考虑TMD分布函数和碎裂函数的演化效应，对高能散射过程中Drell-Yan过程、深度半单举非弹性散射过程、正负电子对湮灭过程中的横极化相关的物理可观测量进行了较为系统的研究，有助于加深我们对QCD动力学和强子内部结构的理解，同时检验因子化定理的有效性。在项目执行期内，项目申请人共发表学术论文10篇，其中第一作者或通讯作者SCI论文6篇、会议论文1篇、参与大科学装置论文署名3篇；另有在投稿SCI论文1篇，草稿阶段论文2篇；基于本项目招收硕士研究生3名，本科生毕业设计2名；1名博士研究生、1名硕士研究生、1名本科生在本项目的资助支持下顺利毕业。