Exploring twist-2 GPDs through quasidistributions in a diquark spectator model
Exploring twist-2 GPDs through quasidistributions in a diquark spectator model
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DOI：
10.1103/physrevd.102.054021
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发表时间：
2019-03
影响因子：
5
通讯作者：
S. Bhattacharya;C. Cocuzza;A. Metz
中科院分区：
文献类型：
--
作者：
S. Bhattacharya;C. Cocuzza;A. Metz
准部分子分布（准PDF）目前正在紧张的调查。准PDF是通过空间相关函数定义的，因此可以在格点QCD中访问。随着强子动量的增加，它们逐渐接近相应的标准（光锥）PDF。最近，我们通过计算标量双夸克旁观者模型中扭曲2矢量的广义部分子分布，研究了广义部分子分布中的准分布概念。在目前的工作中，我们将这项研究扩展到其余六个领先的扭曲GPD。对于大的强子动量，所有的准GPD解析约化为相应的标准GPD。我们还研究了有限强子动量情况下准GPD和标准GPD之间的数值失配。此外，我们提出的准PDF的结果，并探讨与部分子动量和纵向动量转移到目标的高扭曲效应。我们还研究了我们的结果对模型参数的依赖性。最后，我们讨论了准分布的最低阶矩，并详细讨论了准GPD与夸克总角动量的关系。矩分析提出了几个准分布的首选定义。
Quasi parton distributions (quasi-PDFs) are currently under intense investigation. Quasi-PDFs are defined through spatial correlation functions and are thus accessible in lattice QCD. They gradually approach their corresponding standard (light-cone) PDFs as the hadron momentum increases. Recently, we investigated the concept of quasi-distributions in the case of generalized parton distributions (GPDs) by calculating the twist-2 vector GPDs in the scalar diquark spectator model. In the present work, we extend this study to the remaining six leading-twist GPDs. For large hadron momenta, all quasi-GPDs analytically reduce to the corresponding standard GPDs. We also study the numerical mismatch between quasi-GPDs and standard GPDs for finite hadron momenta. Furthermore, we present results for quasi-PDFs, and explore higher-twist effects associated with the parton momentum and the longitudinal momentum transfer to the target. We study the dependence of our results on the model parameters as well. Finally, we discuss the lowest moments of quasi distributions, and elaborate on the relation between quasi-GPDs and the total angular momentum of quarks. The moment analysis suggests a preferred definition of several quasi-distributions.