AI 中文总结
本研究在QCD求和规则框架下计算质子的光子与胶子引力形状因子，发现胶子质量半径小于光子质量半径，为质子引力结构提供了新的非微扰信息。
AI 中文摘要
能量动量张量可揭示能量、动量及力学性质如何在质子的不同量子色动力学（QCD）组分间分布，从而为深入认识质子的内部引力结构提供独特视角。与QCD能量动量张量不同组分相关的引力形状因子，能让我们探究这些部分对质子引力性质的各自贡献。本研究在QCD求和规则框架下计算质子的光子与胶子引力形状因子，利用QCD能量动量张量的光子和胶子组分，推导出对应四个独立引力形状因子的求和规则；在该方法的有效区域内分析其动量传递依赖性，并通过多极参数化外推至零动量传递，将得到的形状因子参数化形式用于提取光子与胶子部分的质量半径和标量半径。结果显示，胶子质量半径小于光子质量半径，表明质子内部的胶子能量分布更局域。这些发现为质子的引力结构提供了新的非微扰信息，也为未来格点QCD计算和唯象研究提供了互补的理论结果。
英文摘要
The energy-momentum tensor provides a unique insight into the internal gravitational structure of the proton by revealing how energy, momentum, and mechanical properties are distributed among its different QCD components. The gravitational form factors associated with different components of the QCD energy-momentum tensor allow us to investigate the individual contributions of these sectors to the gravitational properties of the proton. In this work, we calculate the photon and gluon gravitational form factors of the proton within the framework of QCD sum rules. Using the photon and gluon components of the QCD energy-momentum tensor, we derive the corresponding sum rules for four independent gravitational form factors. Their momentum transfer dependence is analyzed within the validity region of the method and extrapolated to zero momentum transfer using a multipole parametrization. The resulting parametrizations of the form factors are used to extract the mass and scalar radii associated with the photon and gluon sectors. Our results indicate that the gluon mass radius is smaller than the photon mass radius, suggesting a more localized gluonic energy distribution inside the proton. These findings provide new nonperturbative information on the gravitational structure of the proton and offer complementary theoretical results for future lattice QCD calculations and phenomenological studies.
Comments21 Pages, 4 Figures and 3 Tables
