论文标题
纯粹的虚拟颗粒与李及鬼鬼:物理保利谷地,有限的QED和量子重力
Purely virtual particles versus Lee-Wick ghosts: physical Pauli-Villars fields, finite QED and quantum gravity
论文作者
论文摘要
我们重新考虑Lee-Wick(LW)模型,并将其属性与包含纯虚拟颗粒的模型的性质进行比较。我们反对LW前提,即可以从散射过程中的传入和传出状态集中去除不稳定的颗粒。除了与穆恩的观察发生冲突外,拆除导致了非炎症的经典极限。另一方面,如果包括所有状态,LW模型的Hamiltonian均与下方或负规范无关。相反,纯粹的虚拟颗粒导致了荒石的经典限制,并且不在传入和外向状态的集合中,而没有对长期寿命不稳定颗粒的观察产生影响。我们给出一个vademecum来总结大多数治疗异常颗粒的选项的特性。我们通过保存所包含的物理粒子来研究一种仅部分删除LW幽灵的方法。具体而言,我们用纯粹的虚拟粒子和普通粒子的一定叠加代替了LW幽灵,而从外部状态的集合中仅掉落前者。诀窍可用于使Pauli-Villars田地保持一致且可观察,而无需将其群众发送到无限,或通过调整原始的Lee-Wick结构来构建有限的QED。但是,它在一般协方差方面存在问题,因此不能像量子重力一样应用它,而显然协变的分解需要引入大量的Spin-2多重组。
We reconsider the Lee-Wick (LW) models and compare their properties to the properties of the models that contain purely virtual particles. We argue against the LW premise that unstable particles can be removed from the sets of incoming and outgoing states in scattering processes. The removal leads to a non-Hermitian classical limit, besides clashing with the observation of the muon. If, on the other hand, all the states are included, the LW models have a Hamiltonian unbounded from below or negative norms. Purely virtual particles, on the contrary, lead to a Hermitian classical limit and are absent from the sets of incoming and outgoing states without implications on the observation of long-lived unstable particles. We give a vademecum to summarize the properties of most options to treat abnormal particles. We study a method to remove the LW ghosts only partially, by saving the physical particles they contain. Specifically, we replace a LW ghost with a certain superposition of a purely virtual particle and an ordinary particle, and drop only the former from the sets of the external states. The trick can be used to make the Pauli-Villars fields consistent and observable, without sending their masses to infinity, or to build a finite QED, by tweaking the original Lee-Wick construction. However, it has issues with general covariance, so it cannot be applied as is to quantum gravity, where a manifestly covariant decomposition requires the introduction of a massive spin-2 multiplet.