Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Current algebra and soft pionic modes in asymmetric quark matter   Pionic excitations are analyzed in isospin-asymmetric Fermi gas of
constituent quarks. It is found that in addition to the usual pionic
excitations, there exists a very low collective mode with quantum numbers of
the charged pion (spin-isospin sound). In the chiral limit the excitation
energy of one of the modes scales as the current quark mass, and the mode
saturates current-algebraic sum rules. This is in agreement with predictions of
current algebra for isospin-asymmetric medium.

31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
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The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
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The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph