论文标题
Feynman图和其他积分的夹杂性奇异性的Landau条件的新的完整证明
A new and complete proof of the Landau condition for pinch singularities of Feynman graphs and other integrals
论文作者
论文摘要
Landau方程为Feynman振幅中的奇异性如何出现。此外，通过确定渐近问题中动量空间的重要区域，它们是扰动QCD的使用至关重要的。概括也很有用。我们将证明，在现有治疗中，派生存在很大的差距，在某些情况下，在QCD应用中无数的无数含义的情况下，此处将在此显示的隐式假设是错误的。在本文中，有一个新的证据表明，兰道的条件对于以Feynman图象征的那种积分种类来说是必要的，并且足以满足。证明的范围足够宽，可以包括QCD应用程序中使用的修改后的Feynman图。与许多现有推导不同，无需使用Feynman参数方法。提出了新证明及其子公司结果的一些可能进一步的应用。
The Landau equations give a physically useful criterion for how singularities arise in Feynman amplitudes. Furthermore, they are fundamental to the uses of perturbative QCD, by determining the important regions of momentum space in asymptotic problems. Generalizations are also useful. We will show that in existing treatments there are significant gaps in derivations, and in some cases implicit assumptions that will be shown here to be false in important cases like the massless Feynman graphs ubiquitous in QCD applications. In this paper is given a new proof that the Landau condition is both necessary and sufficient for physical-region pinches in the kinds of integral typified by Feynman graphs. The proof's range is broad enough to include the modified Feynman graphs that are used in QCD applications. Unlike many existing derivations, there is no need to use the Feynman parameter method. Some possible further applications of the new proof and its subsidiary results are proposed.
