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arXiv · 1905.00882

Results and techniques for higher order calculations within the gradient-flow formalism

Johannes Artz·Robert V. Harlander·Fabian Lange·Tobias Neumann·Mario Prausa
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Abstract

We describe in detail the implementation of a systematic perturbative approach to observables in the QCD gradient-flow formalism. This includes a collection of all relevant Feynman rules of the five-dimensional field theory and the composite operators considered in this paper. Tools from standard perturbative calculations are used to obtain Green's functions at finite flow time $t$ at higher orders in perturbation theory. The three-loop results for the quark condensate at finite $t$ and the conversion factor for the "ringed" quark fields to the $\overline{\mbox{MS}}$ scheme are presented as applications. We also re-evaluate an earlier result for the three-loop gluon condensate, improving on its accuracy.

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Johannes Artz, Robert V. Harlander, Fabian Lange, Tobias Neumann, Mario Prausa. 2019-05-02. Results and techniques for higher order calculations within the gradient-flow formalism. https://doi.org/10.1007/jhep06(2019)121

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