Gluon Green functions free of Quantum fluctuations

TL;DR

This paper demonstrates that Wilson flow can effectively eliminate quantum fluctuations in gluon Green functions, revealing their classical instanton structure and enabling new applications like instanton detection and lattice calibration.

Contribution

It introduces the use of Wilson flow to remove quantum fluctuations from gluon Green functions, highlighting their classical instanton behavior at different scales.

Findings

Wilson flow removes quantum fluctuations from gluon Green functions.

Post-flow Green functions resemble classical instanton backgrounds.

Potential applications include instanton detection and lattice calibration.

Abstract

This letter reports on how the Wilson flow technique can efficaciously kill the short-distance quantum fluctuations of 2- and 3-gluon Green functions, removes the $\Lambda_{\rm QCD}$ scale and destroys the transition from the confining non-perturbative to the asymptotically-free perturbative sector. After the Wilson flow, the behavior of the Green functions with momenta can be described in terms of the quasi-classical instanton background. The same behavior also occurs, before the Wilson flow, at low-momenta. This last result permits applications as, for instance, the detection of instanton phenomenological properties or a cheap lattice calibration.