Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The quark-gluon vertex in Landau gauge QCD: Its role in dynamical chiral
  symmetry breaking and quark confinement   The infrared behavior of the quark-gluon vertex of quenched Landau gauge QCD
is studied by analyzing its Dyson-Schwinger equation. Building on previously
obtained results for Green functions in the Yang-Mills sector we analytically
derive the existence of power-law infrared singularities for this vertex. We
establish that dynamical chiral symmetry breaking leads to the self-consistent
generation of components of the quark-gluon vertex forbidden when chiral
symmetry is forced to stay in the Wigner-Weyl mode. In the latter case the
running strong coupling assumes an infrared fixed point. If chiral symmetry is
broken, either dynamically or explicitely, the running coupling is infrared
divergent. Based on a truncation for the quark-gluon vertex Dyson-Schwinger
equation which respects the analytically determined infrared behavior numerical
results for the coupled system of the quark propagator and vertex
Dyson-Schwinger equation are presented. The resulting quark mass function as
well as the vertex function show only a very weak dependence on the current
quark mass in the deep infrared. From this we infer by an analysis of the
quark-quark scattering kernel a linearly rising quark potential with an almost
mass independent string tension in the case of broken chiral symmetry.
Enforcing chiral symmetry does lead to a Coulomb type potential. Therefore we
conclude that chiral symmetry breaking and confinement are closely related.
Furthermore we discuss aspects of confinement as the absence of long-range
van-der-Waals forces and Casimir scaling. An examination of experimental data
for quarkonia provides further evidence for the viability of the presented
mechanism for quark confinement in the Landau gauge.

17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph