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arXiv 1801.00526hep-phhep-exhep-thnucl-th
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用三维结构函数计算强子的层析成像和引力半径

Tomography and gravitational radii for hadrons by three-dimensional structure functions

S. Kumano, Qin-Tao Song, O. V. Teryaev

摘要:

强子的三维层析成像可以用广义部分子分布(GPD)、横动量相关部分子分布(TMD)和广义分布振幅(GDA)来研究。GDA的研究长期以来只是理论上的,因为直到最近才有实验测量,而GPD和TMD已经通过深度虚康普顿散射和半包含深度非弹性散射进行了广泛的研究。在这里,我们报告我们的研究,以确定π GDA从最近KEKB测量的微分截面的$γ^* γ\to π^0 π^0$。由于奇异强子对可以在末态产生,GDA也可以用于探测奇异强子候选者的内部结构。GDA的另一个重要特征是GDA包含了夸克和胶子的能量-动量张量的形状因子的信息,因此可以从确定的GDA计算引力形状因子和半径。我们显示的质量(能量)和机械(压力,剪切力)形状因子和半径的π介子。本文的分析是首次尝试通过对实际实验测量的分析来获得强子的引力形状因子和半径。我们相信,一个新的领域的引力物理是从微观水平上创建的基本夸克和胶子。

英文摘要:

Three-dimensional tomography of hadrons can be investigated by generalized parton distributions (GPDs), transverse-momentum-dependent parton distributions (TMDs), and generalized distribution amplitudes (GDAs). The GDA studies had been only theoretical for a long time because there was no experimental measurement until recently, whereas the GPDs and TMDs have been investigated extensively by deeply virtual Compton scattering and semi-inclusive deep inelastic scattering. Here, we report our studies to determine pion GDAs from recent KEKB measurements on the differential cross section of $γ^* γ\to π^0 π^0$. Since an exotic-hadron pair can be produced in the final state, the GDAs can be used also for probing internal structure of exotic hadron candidates in future. The other important feature of the GDAs is that the GDAs contain information on form factors of the energy-momentum tensor for quarks and gluons, so that gravitational form factors and radii can be calculated from the determined GDAs. We show the mass (energy) and the mechanical (pressure, shear force) form factors and radii for the pion. Our analysis should be the first attempt for obtaining gravitational form factors and radii of hadrons by analysis of actual experimental measurements. We believe that a new field of gravitational physics is created from the microscopic level in terms of elementary quarks and gluons.

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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