Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Quark-Level Linear \sigma\ Model   This review of the quark-level linear \sigma model is based upon the
dynamical realization of the pseudoscalar and scalar mesons as a linear
representation of SU(2) x SU(2) chiral symmetry, with the symmetry weakly
broken by current quark masses. In its simplest SU(2) incarnation, with two
non-strange quark flavors and three colors, this nonperturbative theory, which
can be selfconsistently bootstrapped in loop order, is shown to accurately
reproduce a host of low-energy observables with only one parameter, namely the
pion decay constant f_\pi. Extending the scheme to SU(3) by including the
strange quark, equally good results are obtained for many strong,
electromagnetic, and weak processes just with two extra constants, viz. f_K and
$\langle\pi|H_{\mbox{\scriptsize weak}}|K\rangle$. Links are made with the
vector-meson-dominance model, the BCS theory of superconductivity, and
chiral-symmetry restoration at high temperature. Finally, these ideas are
cautiously generalized to the electroweak sector, including the W, Z, and Higgs
bosons, and also to CP violation.

22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys