QED in the Exact Renormalization Group
QED in the Exact Renormalization Group
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精确重正化群中的 QED
DOI：
10.1093/ptep/ptab142
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Katsumi Itoh
中科院分区：
文献类型：
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作者：
Yuji Igarashi;Katsumi Itoh
在微扰下一致地求解了有和无四费米相互作用的手征对称QED的泛函流方程和量子主方程。由于动量截止的存在，即使在我们的微扰结果中也观察到了与规范对称性有关的非常规特征。在没有四费米耦合的情况下，一个单圈计算给了我们反常尺寸的标准结果和规范耦合的β函数，因此是沃德恒等式，Z1=Z2。这是单循环计算中正则化方案独立性的结果。我们还发现了一个光子质量项。当包含四费米耦合时，四费米耦合对β函数有贡献，沃德恒等式也被修改，Z1 <$Z2，这是由于一个与光子质量乘以四费米耦合成正比的项。
The functional flow equation and the quantum master equation are consistently solved in perturbation for chiral symmetric QED with and without four-fermi interactions. Due to the presence of a momentum cutoff, unconventional features related to gauge symmetry are observed even in our perturbative results. In the absence of the four-fermi couplings, a one-loop calculation gives us the standard results of anomalous dimensions and the beta function for the gauge coupling, and therefore the Ward identity,Z1=Z2. This is a consequence of the regularization-scheme independence in the one-loop computation. We also find a photon mass term. When included, four-fermi couplings contribute to the beta function and the Ward identity is also modified,Z1≠Z2, due to a term proportional to the photon mass multiplied by the four-fermi couplings.