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arXiv 0712.1012hep-ph
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手征夸克模型中π介子的广义部分子分布及其QCD演化

Generalized parton distributions of the pion in chiral quark models and their QCD evolution

Wojciech Broniowski, Enrique Ruiz Arriola, Krzysztof Golec-Biernat

摘要:

本文计算了两种手征夸克模型:谱夸克模型和Pauli-Villars正则化的Nambu-Jona-Lasinio模型中π介子的广义部分子分布。我们继续通过使用一个明显的协变计算的基础上的阿尔法表示的传播的双分布的评价。因此,多项式被自动合并,计算变得简单。此外,正性和规范化约束,求和规则和软π介子定理得到满足。我们得到明确的公式,在低能夸克模型尺度。该表达式在t依赖性中没有表现出因式分解。这些部分子分布的QCD演化进行到实验或晶格可达的尺度。我们通过比较π介子的部分子分布函数和部分子分布振幅与现有的实验和晶格数据,论证了演化的必要性,并证实夸克模型的尺度很低,约为320 MeV。

英文摘要:

We evaluate Generalized Parton Distributions of the pion in two chiral quark models: the Spectral Quark Model and the Nambu-Jona-Lasinio model with a Pauli-Villars regularization. We proceed by the evaluation of double distributions through the use of a manifestly covariant calculation based on the alpha representation of propagators. As a result polynomiality is incorporated automatically and calculations become simple. In addition, positivity and normalization constraints, sum rules and soft pion theorems are fulfilled. We obtain explicit formulas, holding at the low-energy quark-model scale. The expressions exhibit no factorization in the t-dependence. The QCD evolution of those parton distributions is carried out to experimentally or lattice accessible scales. We argue for the need of evolution by comparing the Parton Distribution Function and the Parton Distribution Amplitude of the pion to the available experimental and lattice data, and confirm that the quark-model scale is low, about 320 MeV.

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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