Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: QCD sum rules for rho mesons in nuclear matter   We investigate QCD sum rules for vector currents in the rho meson channel in
the nuclear medium. For increased sensitivity, we subtract out the vacuum
contributions. With a saturation scheme often considered in the literature, we
find these subtracted sum rules to be unstable. It indicates the importance of
other contributions neglected in the saturation scheme. These include more
Landau singularities at low energy, additional operators in the medium, and
possibly the in-medium width of the rho meson.

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The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
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The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
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The categories of this paper are: eess
29
The categories of this paper are: funct-an
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The categories of this paper are: math
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs