Estudo Geralhttps://estudogeral.uc.ptThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Fri, 08 Dec 2023 12:03:08 GMT2023-12-08T12:03:08Z5011The quark-gluon vertex and the QCD infrared dynamicshttps://hdl.handle.net/10316/106926Title: The quark-gluon vertex and the QCD infrared dynamics
Authors: Oliveira, Orlando; de Paula, Wayne; Frederico, Tobias; de Melo, J. P. B. C
Abstract: The Dyson–Schwinger quark equation is solved
for the quark-gluon vertex using the most recent lattice data
available in the Landau gauge for the quark, gluon and
ghost propagators, the full set of longitudinal tensor structures
in the Ball-Chiu vertex, taking into account a recently
derived normalisation for a quark-ghost kernel form factors
and the gluon contribution for the tree level quark-gluon
vertex identified on a recent study of the lattice soft gluon
limit. A solution for the inverse problem is computed after
the Tikhonov linear regularisation of the integral equation,
that implies solving a modified Dyson–Schwinger equation.
We get longitudinal form factors that are strongly enhanced
at the infrared region, deviate significantly from the tree level
results for quark and gluon momentum below 2 GeV and at
higher momentum approach their perturbative values. The
computed quark-gluon vertex favours kinematical configurations
where the quark momentum p and the gluon momentum
q are small and parallel. Further, the quark-gluon vertex
is dominated by the form factors associated to the tree level
vertex γμ and to the operator 2 pμ + qμ. The higher rank
tensor structures provide small contributions to the vertex.
Tue, 01 Jan 2019 00:00:00 GMThttps://hdl.handle.net/10316/1069262019-01-01T00:00:00Z