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Main Author: Peruzzo, Giovani
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2501.17138
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author Peruzzo, Giovani
author_facet Peruzzo, Giovani
contents In general, in gauge field theories, physical observables are represented by gauge-invariant composite operators, such as the electromagnetic current. As we recently demonstrated in the context of the $U\left(1\right)$ and $SU\left(2\right)$ Higgs models \cite{Dudal:2019pyg,Dudal:2020uwb,Maas:2020kda}, correlation functions of gauge-invariant operators exhibit very nice properties. Besides the well-known gauge independence, they do not present unphysical cuts, and their Källén-Lehmann representations are positive, at least perturbatively. Despite all these interesting features, they are not employed as much as elementary fields, mainly due to the additional complexities involved in their computation and renormalization. In this article, we present a useful trick to compute loop corrections to correlation functions of composite operators. This trick consists of introducing an additional field with no dynamics, coupled to the composite operator of interest. By using this approach, we can employ the traditional algorithms used to compute correlation functions of elementary fields.
format Preprint
id arxiv_https___arxiv_org_abs_2501_17138
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Useful trick to compute correlation functions of composite operators
Peruzzo, Giovani
High Energy Physics - Theory
Mathematical Physics
In general, in gauge field theories, physical observables are represented by gauge-invariant composite operators, such as the electromagnetic current. As we recently demonstrated in the context of the $U\left(1\right)$ and $SU\left(2\right)$ Higgs models \cite{Dudal:2019pyg,Dudal:2020uwb,Maas:2020kda}, correlation functions of gauge-invariant operators exhibit very nice properties. Besides the well-known gauge independence, they do not present unphysical cuts, and their Källén-Lehmann representations are positive, at least perturbatively. Despite all these interesting features, they are not employed as much as elementary fields, mainly due to the additional complexities involved in their computation and renormalization. In this article, we present a useful trick to compute loop corrections to correlation functions of composite operators. This trick consists of introducing an additional field with no dynamics, coupled to the composite operator of interest. By using this approach, we can employ the traditional algorithms used to compute correlation functions of elementary fields.
title Useful trick to compute correlation functions of composite operators
topic High Energy Physics - Theory
Mathematical Physics
url https://arxiv.org/abs/2501.17138