论文标题
仪表不变性和红外线的背景上振幅的分析结构
The analytic structure of amplitudes on backgrounds from gauge invariance and the infra-red
论文作者
论文摘要
规格不变性和软限制足以确定某些理论中散射幅度的分析结构。这提示了一个问题，即在更一般的理论中如何连接量规不变性。在这里，我们专注于背景平面波中的QED。我们表明，施加量规的不变性将新的虚拟电线杆引入了内部动量，将其分量分解为一系列术语。每个术语都是规格不变的，在外部动量中具有不同的分析结构，并且表现出硬/软分子化。引入的极点由红外行为决定，这使我们能够将结果扩展到标量Yukawa理论。整个背景都非扰动地处理。
Gauge invariance and soft limits can be enough to determine the analytic structure of scattering amplitudes in certain theories. This prompts the question of how gauge invariance is connected to analytic structure in more general theories. Here we focus on QED in background plane waves. We show that imposing gauge invariance introduces new virtuality poles into internal momenta on which amplitudes factorise into a series of terms. Each term is gauge invariant, has a different analytic structure in external momenta, and exhibits a hard/soft factorisation. The introduced poles are dictated by infra-red behaviour, which allows us to extend our results to scalar Yukawa theory. The background is treated non-perturbatively throughout.
