This work applies lattice QCD to compute quark momentum distributions in the nucleon. We explore a novel approach based on non-local operators in order to analyze transverse momentum dependent parton distribution functions, which encode information about the intrinsic motion of quarks inside the nucleon. Our calculations are based on MILC gauge configurations and domain wall fermion propagators from LHPC. One interesting observation is that the transverse momentum dependent density of polarized quarks in a polarized nucleon is visibly deformed. Moreover, we can test the assumption that longitudinal and transverse momentum dependence factorize within a certain kinematical region. A more elaborate operator geometry is required to enable a quantitative comparison to azimuthal asymmetries observable in experiments such as semi-inclusive deeply inelastic scattering, and to study time-reversal odd distributions such as the Sivers function. First steps in this direction are encouraging.
Transverse momentum-dependent parton distributions for longitudinally polarized nucleons from domain wall fermion calculations at the physical pion mass
Transverse spin structure of the nucleon from lattice QCD simulations
本文首次在格点量子色动力学中计算了核子中夸克横自旋密度的最低两阶矩。它们编码了夸克自旋和轨道角动量之间的相关性。我们的动力学模拟是基于两种风格的三叶草改进的威尔逊费米子和威尔逊胶子。我们发现某些夸克螺旋度翻转广义部分子分布的显着贡献，导致强烈扭曲的核子中的横向极化夸克的密度。特别地，基于我们的结果和Burkardt [Phys. Rev. D 72（2005）094020]的最新论证，我们预测了描述横夸克自旋和夸克内禀横动量关联的Boer-Mulders函数$h_1^\perp$对于上夸克和下夸克都是大的且为负的。
Light-Front Transverse Nucleon Charge and Magnetisation Densities
Universidad de Huelva（韦尔瓦大学）；Helmholtz-Zentrum Dresden-Rossendorf（德累斯顿-罗森多夫亥姆霍兹中心）；Anhui Normal University（安徽师范大学）；Nanjing University（南京大学）；Institute for Nonperturbative Physics, Nanjing University（南京大学非微扰物理研究所）；Univ. Pablo de Olavide（巴勃罗·德·奥拉维德大学）
Existence of nuclear modifications on longitudinal-transverse structure-function ratio
Institute of Modern Physics, Chinese Academy of Sciences（中国科学院近代物理研究所）；Southern Center for Nuclear Science Theory, Institute of Modern Physics, Chinese Academy of Sciences（中国科学院近代物理研究所南方核科学理论中心）；Faculty of Science, Japan Women’s University（日本女子大学理学部）；KEK Theory Center, Institute of Particle and Nuclear Studies, KEK（高能加速器研究机构粒子与核研究所学部理论中心）
