Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the determination of the pion effective mass in nuclei from pionic
  atoms   The binding energies of the deeply bound 1s and 2p states in pionic atoms of
$^{207}$Pb, recently established experimentally in the $^{208}$Pb(d,$^3$He)
reaction, have been used by several groups to derive the pion effective mass in
nuclear matter. We show that these binding energies are fully consistent with
`normal' pionic atoms and that the real part of the pion-nucleus potential at
the center of $^{207}$Pb is 28$\pm$3 MeV and not 20 MeV as suggested
previously.

36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
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The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom