Integrating out new fermions at one loop
Integrating out new fermions at one loop
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DOI：
10.1007/jhep01(2021)049
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发表时间：
2021-01-11
影响因子：
5.4
通讯作者：
Huang, Peisi
中科院分区：
文献类型：
--
作者：
Angelescu, Andrei;Huang, Peisi
本文给出了用泛函技术在一个环积分出重向量费米子得到的费米子通用单环有效作用。尽管以前的方法能够处理重费米子与非手性相互作用的积分，即消失伽马(5)相互作用项，但计算过程繁琐，难以进行物理解释。我们展示了如何直接处理费米子泛函行列式不仅允许更简单和透明的计算，而且还能够以简单的算法方式解释手性相互作用项。最后，我们将得到的结果应用于在一个循环中积分出现在玩具模型和表现出强宇宙相变的费米子模型中的向量费米子。
We present the fermionic universal one-loop effective action obtained by integrating out heavy vector-like fermions at one loop using functional techniques. Even though previous approaches are able to handle integrating out heavy fermions with non-chiral interactions, i.e. vanishing gamma(5) interaction terms, the computations proceed in a tedious manner that obscures a physical interpretation. We show how directly tackling the fermionic functional determinant not only allows for a much simpler and transparent computation, but is also able to account for chiral interaction terms in a simple, algorithmic way. Finally, we apply the obtained results to integrate out at one loop the vector-like fermions appearing in a toy model and in a fermionic model that exhibits strong cosmological phase transitions.