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arXiv 2302.07473hep-phhep-latnucl-exnucl-th
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核子自旋与动量的部分子分解：来自穿衣服夸克的胶子

Parton Decomposition of Nucleon Spin and Momentum: Gluons from Dressed Quarks

Peter C. Tandy

备注：
8 pages, 5 figures. Submitted for publication. This version clarifies and qualifies the approach and methods, and corrects typing errors
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AI总结：

本研究基于QCD戴森-施温格方程的彩虹-梯截断模型，探究核子中夸克与胶子的自旋、动量贡献，纳入π介子云后质子角动量与实验偏差在1%以内，揭示了角动量的轨道与内禀自旋均分特性。

摘要：

我们在一个可探究夸克与胶子贡献相互关联的模型中，研究了强子广义部分子分布的最低两个梅林矩。对于轻夸克而言，由于夸克的穿衣服效应，二者的动力学关联很强。本研究的核心焦点是核子的角动量$J$。本工作采用并拓展了我们近期针对π介子和核子中夸克与胶子动量份额$\u27e8 x \u27e9_{\rm q/g}$的模型研究所得的动力学洞见。所采用的模型基于QCD戴森-施温格方程的彩虹-梯截断。我们使用单强子夸克的1圈处理这一特殊情形来引出若干洞见并得到初步估计值，例如对已建立的朗道规范模型的威尔逊线修正（对$J_{\rm q}$和$\u27e8 x \u27e9_{\rm q}$均为$-7\\%$），以及“束缚胶子”对$\u27e8 x \u27e9_{\rm g}$的贡献（$\leq 10\\%$）。在纳入π介子云机制以产生海夸克后，我们得到的质子角动量$J$与实验值的偏差在1%以内。质子的胶子第二梅林矩反映了相似的动力学：在模型标度下，$(\u27e8 x \u27e9_{\rm g}, J_{\rm g})$为(26%, 24%)，在2 GeV标度下为(40%, 38%)。我们还发现，总角动量$J_{\rm tot}$几乎在总轨道角动量贡献与总内禀自旋贡献之间均分。

英文摘要：

The lowest two Mellin moments of hadronic Generalized Parton Distributions are explored within a model that allows investigation of the inter-related quark and gluon contributions. For light quarks their dynamical connection is strong due to quark dressing. Our principal focus is the angular momentum $J$ of the nucleon. This work employs and extends dynamical insights obtained from our recent model results for quark and gluon momentum fractions $\langle x \rangle_{\rm q/g}$ in both pion and nucleon. The employed model is based on the Rainbow-Ladder truncation of the Dyson-Schwinger equations of QCD. The special case of a 1-loop treatment of a single hadronic quark is used to motivate several insights and obtain initial estimates such as the Wilson line correction to the established Landau gauge model ($ -7\%$ for both $J_{\rm q}$ and $\langle x \rangle_{\rm q}$), and the "binding gluon" contribution to $\langle x \rangle_{\rm g}$ ($\leq 10\%$). We obtain the proton $J$ within 1\% after inclusion of the pion cloud mechanism to produce the sea. The gluon second Mellin moments of the proton reflect similar dynamics; ($\langle x \rangle_{\rm g}$, $J_{\rm g}$) are (26\% , 24\%) at model scale, and (40\%, 38\%) at $2$ GeV. We also find that $J_{\rm tot}$ is shared almost equally between the total orbital and total intrinsic spin contributions.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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