Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quarks, mesons and (exact) flow equations   Dynamical chiral symmetry breaking is described within the linear sigma model
of QCD coupled to quarks. The main technical tool used for this intrinsically
non--perturbative problem is an exact renormalization group equation for the
quantum effective action. It is demonstrated that realistic values for
phenomenological quantities like the pion decay constant, constituent quark
masses or the chiral condensate are obtainable.

36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat