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arXiv 2207.09892hep-ph
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单重态算子到四个环的重正化

Renormalisation of singlet operators to four loops

Giulio Falcioni

摘要:

在QCD中,扭2规范不变算符的反常维度发挥着关键作用,因为它们控制着部分子分布函数的标度依赖性。值得注意的是,味单态算符,例如那些与胶子分布相关的算符,在重整化下与一组非物理算符混合,也被称为外星人。忽略这种效应会导致双环反常维数的错误结果。胶子算符的正确重整化是计算味单重态部分子分布尺度演化的重要一步,现在需要4个循环。利用背景场方法和增强的BRST对称性,我们构建了所需的鬼和外来运营商的基础上,任意质量尺寸的4个循环。此外,我们提取异常尺寸在4个循环,质量维4和6的物理运营商,并在3个循环的质量维8。

英文摘要:

In QCD the anomalous dimensions of gauge invariant operators of twist 2 play a key role, because they control the scale dependence of the parton distribution functions. Notably, the flavour singlet operators, such as those associated to the gluon distribution, mix under renormalisation with a set of unphysical operators, also known as aliens. Missing this effect leads to wrong results already for the two-loop anomalous dimensions. The correct renormalisation of gluonic operators is an important step towards the computation of the scale evolution of flavour singlet parton distributions, which is now required to 4 loops. Leveraging both the background field method and an enhanced BRST symmetry, we construct the required ghost and alien operator basis up to 4 loops for arbitrary mass dimensions. Furthermore, we extract anomalous dimensions at 4 loops, for the physical operators of mass-dimension 4 and 6, and at 3 loops for mass-dimension 8.

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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