标题： 夸克Wigner分布和轨道角动量 显示英文标题

标题： Quark Wigner Distributions and Orbital Angular Momentum

摘要： 我们研究核子的维格纳函数，这些函数提供了相空间中夸克分布的多维图像。 这些函数可以通过广义横向动量依赖部分子分布的横向空间中的傅里叶变换获得。 它们既依赖于相对于核子的夸克的横向位置，又依赖于其三维动量，因此在一个图像中结合了广义部分子分布和横向动量依赖部分子分布中的所有信息。 我们将讨论集中在非极化/纵向极化的夸克在非极化/纵向极化的核子中的分布上。 这样，我们可以研究夸克轨道角动量在塑造核子及其与夸克和核子极化相关性中的作用。 夸克轨道角动量还可以从其相空间平均值计算得出，该平均值以纵向极化的核子中非极化夸克的维格纳分布为权重。 在不同的轻锥夸克模型中得到的相应结果与以广义部分子分布和横向动量依赖部分子分布形式给出的夸克轨道角动量的其他定义进行了比较。 显示英文摘要

摘要： We study the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space. These functions can be obtained through a Fourier transform in the transverse space of the generalized transverse-momentum dependent parton distributions. They depend on both the transverse position and the three-momentum of the quark relative to the nucleon, and therefore combine in a single picture all the information contained in the generalized parton distributions and the transverse-momentum dependent parton distributions. We focus the discussion on the distributions of unpolarized/longitudinally polarized quark in an unpolarized/longitudinally polarized nucleon. In this way, we can study the role of the orbital angular momentum of the quark in shaping the nucleon and its correlations with the quark and nucleon polarizations. The quark orbital angular momentum is also calculated from its phase-space average weighted with the Wigner distribution of unpolarized quarks in a longitudinally polarized nucleon. The corresponding results obtained within different light-cone quark models are compared with alternative definitions of the quark orbital angular momentum, as given in terms of generalized parton distributions and transverse-momentum dependent parton distributions.