Electric field decay without pair production: lattice, bosonization and novel worldline instantons
Electric field decay without pair production: lattice, bosonization and novel worldline instantons
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DOI：
10.1007/jhep03(2022)197
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发表时间：
2021-07
影响因子：
5.4
通讯作者：
Xu-Yao Hu;M. Kleban;Cedric Yu
中科院分区：
文献类型：
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作者：
Xu-Yao Hu;M. Kleban;Cedric Yu
电场可以通过施温格效应自发地衰减，即由临界距离d分开的带电粒子-反粒子对的成核。如果可用距离小于d，会发生什么？以前关于这个问题的工作产生了相互矛盾的结果。在这里，我们研究了电场的量子演化时，在一个紧凑的方向指向周长L <d使用大量的Schwinger模型，量子电动力学在一个空间维与大量的带电费米子。我们发现了一组新的和以前未知的瞬子，导致新的物理，不同意所有以前的估计。在量子理论中，场值可以定义得很好的参数体系中，一般的初始场E实际上是稳定的，不会衰减，而以电荷E =（k/2）g的半整数单位量子化的初始值，k ∈ N，在时间上从+（k/2）g振荡到−（k/2）g，以指数小的概率取任何其他值。我们验证了我们的结果与四个不同的技术：数值上直接测量在洛伦兹时间的晶格上的衰变，数值上使用的哈密顿量的频谱，数值上和半解析使用玻色子描述的Schwinger模型，并通过我们的瞬子估计分析。
Electric fields can spontaneously decay via the Schwinger effect, the nucleation of a charged particle-anti particle pair separated by a critical distance d. What happens if the available distance is smaller than d? Previous work on this question has produced contradictory results. Here, we study the quantum evolution of electric fields when the field points in a compact direction with circumference L< d using the massive Schwinger model, quantum electrodynamics in one space dimension with massive charged fermions. We uncover a new and previously unknown set of instantons that result in novel physics that disagrees with all previous estimates. In parameter regimes where the field value can be well-defined in the quantum theory, generic initial fields E are in fact stable and do not decay, while initial values that are quantized in half-integer units of the charge E=(k/2) g with k∈ ℤ oscillate in time from+(k/2) g to−(k/2) g, with exponentially small probability of ever taking any other value. We verify our results with four distinct techniques: numerically by measuring the decay directly in Lorentzian time on the lattice, numerically using the spectrum of the Hamiltonian, numerically and semi-analytically using the bosonized description of the Schwinger model, and analytically via our instanton estimate.