论文标题
穿着 - 肿瘤状态和QED红外物理
Dressed-Asymptotic States and QED Infrared Physics
论文作者
论文摘要
穿着的状态形式主义将软颗粒的相互作用融合到渐近状态，被称为有望解决量子场理论（QFT）中红外（IR）差异问题的处方。一个特别著名的例子是Kulish和Faddeev在量子电动力学（QED）中提出的着装状态形式主义。正如Hirai和Sugishita所指出的那样，这种形式主义在规格不变性和IR差异方面存在问题。这些问题主要是由于幽灵或非物理光子模式的存在引起的。因此，我们首先研究库仑仪中的渐近状态，该状态排除了幽灵和/或非物理光子模式。在本文中，我们提出了一种形式主义，通过设置足够大的时间尺度$ t $来直接从理论的相互作用中构建渐近状态。在这种穿着的状态形式主义中，我们根据$ 1/t $的某些固定顺序定义剩余的渐近互动，并根据该订单执行所有计算。我们专门研究了QED中的渐近状态，但是我们可以正式将本文中提出的穿着状态形式施加到任何扰动QFT中。我们表明，至少在QED中，我们可以使用本文提议的穿着状态来构建无差异和统一的$ s $ -matrix。此外，我们讨论了过渡速率，以表明我们可以预测实验结果。我们还表明，$ \ mathrm {u}（1）$ $ s $ -matrix的量规对称会导致QED大量量规对称性，并且在初始和最终空格式超曲面之间出现了向量电位的期望值偏差，这是QED的内存效应。在本文中，穿着的状态形式主义可以对IR物理学有一个统一的新见解，包括渐近对称性，记忆效应和状态进化的单位性。
The dressed state formalisms, which incorporate interactions of soft particles into an asymptotic state, are known as the prescriptions expected to solve the problem of infrared (IR) divergence in the quantum field theory (QFT). A particularly famous example is the dressed state formalism proposed by Kulish and Faddeev in quantum electrodynamics (QED). As pointed out by Hirai and Sugishita, however, this formalism has problems in gauge invariance and the IR divergence. These problems are mainly caused by the existence of ghosts or unphysical photon modes. Therefore, we start by studying the asymptotic states in the Coulomb gauge, which excludes ghosts and/or unphysical photon modes. In this paper, we propose a formalism to construct the asymptotic states directly from the interaction of the theory by setting a sufficiently large time scale $T$. In this dressed state formalism, we define the asymptotic interaction remaining at $|t|>T$ in terms of some fixed order of $1/T$, and we are performing all calculations according to that order. We study the asymptotic states in QED specifically, but we can formally apply the dressed state formalism proposed in this paper to any perturbative QFT. We show that, at least in QED, we can construct divergence-free and unitary $S$-matrix using dressed states proposed in this paper. Furthermore, we discuss the transition rate to show that we can predict experimental results. We also show that the $\mathrm{U}(1)$ gauge symmetry of $S$-matrix leads to the QED large gauge symmetry, and deviation of the expectation values of the vector potential between initial and final spacelike hypersurfaces emerges as a QED memory effect. The dressed state formalism in this paper may give a unified and new insight into IR physics, including asymptotic symmetries, memory effects, and unitarity of the state evolution.
