论文标题
QCD的一环的双重电流
Double soft current at one-loop in QCD
论文作者
论文摘要
我们研究了具有多个硬腿的QCD振幅的柔软行为，并在一环处提出了双重胶状和双重夸克的紧凑表达。电流的颜色相关性基本上显示了一个偶极结构，该结构一次将其耦合到两条硬腿，除了简单的Abelian贡献，该贡献将其作为一环和树级的单个软电流的产品分配，该产品最多将三个硬腿耦合。运动学依赖性可以用多聚集体表示（至少在$ε$中为有限项），结果以类似时间的运动学显示。然后，讨论分析延续到其他运动学构型，我们发现我们发现非平凡的交叉处进入ingoing状态。振幅平方总是越过不变的，这导致这样一个事实，即完全差异的软函数（和TMD软函数）是通用的，直至三环。
We study the soft behavior of QCD amplitudes with multiple hard legs and present a compact expression for double soft gluons and double soft quarks at one-loop. The color correlation of the current basically shows a dipole structure which couples to two hard legs at one time, except for a simple abelian contribution which factorizes as products of one-loop and tree-level single soft current which couples up to three hard legs. The kinematic dependence can be expressed in terms of polylogarithms (at least up to finite terms in $ε$) and the results were displayed with time-like kinematics. Analytical continuation to other kinematic configurations is then discussed where we found non-trivial crossing into ingoing states. The amplitude squared is always crossing invariant, which leads to the fact that the fully differential soft function (and the TMD soft function) is universal up to three-loop.
