Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chiral Symmetry Restoration and the sigma-meson   The sigma-meson, which is at best a broad resonance in the vacuum, may suffer
a substantial red-shift and appear as a soft and narrow collective mode at
finite temperature and baryon densities. The physics behind this softening
phenomena and its relation to the partial restoration of chiral symmetry are
discussed. Possible experiments in laboratory to test the idea are also
summarized.

20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph