A forest formula to subtract infrared singularities in amplitudes for wide-angle scattering
A forest formula to subtract infrared singularities in amplitudes for wide-angle scattering
复制标题
用于减去广角散射的红外振幅奇点的森林公式
DOI：
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Yao Ma
中科院分区：
文献类型：
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作者：
Yao Ma
对于任何具有无质量部分子的硬QCD振幅，红外（IR）奇异性产生于圈动量复平面（称为箍缩面）中的箍缩。为了组织和研究它们在这些曲面邻域中的主导行为，我们可以构造共线和软奇点的近似算子。可以开发一个类似BPHZ的森林公式来系统地减去它们。本文利用Erdogan和Sterman对绿色函数的位置空间分析，发展了动量空间的形式。柯林斯对苏达科夫形状因子进行了相关的分析，并在这里推广到具有任意数量外动量的任何广角运动学。我们将首先看到近似产生比原始振幅丰富得多的IR结构，然后构造森林公式并证明其减法项中出现的所有奇点成对抵消。在森林公式的帮助下，全振幅也可以重组成一个因式分解的表达式，这有助于将Sudakov形状因子的结果推广到任意数量的外动量。我们所有的分析都将在振幅水平上进行。
For any hard QCD amplitude with massless partons, infrared (IR) singularities arise from pinches in the complex planes of loop momenta, called pinch surfaces. To organize and study their leading behaviors in the neighborhoods of these surfaces, we can construct approximation operators for collinear and soft singularities. A BPHZ-like forest formula can be developed to subtract them systematically. In this paper, we utilize the position-space analysis of Erdoğan and Sterman for Green functions, and develop the formalism for momentum space. A related analysis has been carried out by Collins for the Sudakov form factors, and is generalized here to any wide-angle kinematics with an arbitrary number of external momenta. We will first see that the approximations yield much richer IR structures than those of an original amplitude, then construct the forest formula and prove that all the singularities appearing in its subtraction terms cancel pairwise. With the help of the forest formula, the full amplitude can also be reorganized into a factorized expression, which helps to generalize the Sudakov form factor result to arbitrary numbers of external momenta. All our analysis will be on the amplitude level.
影响因子：
5.4
作者：
Del Duca V
通讯作者：
Del Duca V
影响因子：
5.4
作者：
Anastasiou, Charalampos;Sterman, George
通讯作者：
Sterman, George