|
Résumé |
In the new model [1] of non-perturbative Quantum Chromodynamics extra fields are introduced to solve the Gribov problem. But these fields can be exploited to solve other problems.
As a first project we connect these fields to Landau-Khalatnikov-Fradkin transformations. These LKFT's are introduced as a tool to interpolate n-point correlations functions between different gauges. This way one would be able to link the gluon propagator between different gauges, meaning that one could calculate the propagator in one gauge and find the required correction factor to transform this result to another gauge.
As proof of concept these allow to replicate the known Abelian results, but the formalism can be expanded to non-Abelian theories or it can be used to include fermions.
In a second item we take a look at another consequence of these fields, namely the extra vertices and propagators that arrive. More precisely, we take a look at the gluon self-energy, up to first order corrections and the extra diagrams that arrive. In particular we look further at a subset of diagrams which are all log-divergent, but we attempt to resum these and find (surprisingly) a convergent result.
Furthermore, these results are mapped with Renormalisation Group results in order to fit the gluon mass parameter to lattice data.
[1] Non-perturbative aspects of Euclidean Yang-Mills theories in linear covariant gauges: Nielsen identities and a BRST invariant two-point correlation function
Capri, Dudal, Pereira, Fiorentini, Guimaraes, Mintz, Palhares, Sorella
arXiv: 1611.10077v2 |
