Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Yang-Mills Propagators and QCD   We present a strong coupling expansion that permits to develop analysis of
quantum field theory in the infrared limit. Application to a quartic massless
scalar field gives a massive spectrum and the propagator in this regime. We
extend the approach to a pure Yang-Mills theory obtaining analogous results.
The gluon propagator is compared satisfactorily with lattice results and
similarly for the spectrum. Comparison with experimental low energy spectrum of
QCD supports the view that $\sigma$ resonance is indeed a glueball. The gluon
propagator we obtained is finally used to formulate a low energy Lagrangian for
QCD that reduces to a Nambu-Jona-Lasinio model with all the parameters fixed by
those of the full theory.

7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an