Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Three-pion exchange: a gap in the nucleon-nucleon potential   The leading contribution to the three-pion exchange nucleon-nucleon potential
is calculated in the framework of chiral symmetry. It has pseudoscalar and
axial components and is dominated by the former, which has a range of about 1.5
fm and tends to enhance the OPEP. The strength of this force does not depend on
the pion mass and hence it survives in the chiral limit.

7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol