Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Structure for the breathing mode of the nucleon from high energy p-p
  scattering   Spectra of p-p and pi-p scattering at beam momenta between 6 and 30 GeV/c
have been reanalysed. These show strong excitation of N* resonances, the
strongest one corresponding to the "scalar" P11 excitation (breathing mode) at
m_o= 1400+-10 MeV with Gamma= 200+-25 MeV. The result of a strong scalar
excitation is supported by a large longitudinal amplitude S_1/2 extracted from
e-p scattering. From exclusive data on p+p=>p p pi+ pi- a large 2pi-N decay
branch for the P_11 resonance of B_2pi= 75+-20 % has been extracted.
  The differential cross sections were described in a double folding approach,
assuming multi-gluon exchange as the dominant part of the effective interaction
between the constituents of projectile and target. First, the parameters of the
interaction were fitted to elastic scattering; then with this interaction the
inelastic cross sections were described in the distorted wave Born
approximation. A good description of the data requires a surface peaked
transition density, quite different from that of a pure radial mode. In
contrast, the electron scattering amplitude S_1/2 is quite well described by a
breathing mode transition density with radial node. This large difference
between charge and matter transition density suggests, that in p-p scattering
the coupling to the multi-gluon field is much more important than the coupling
to the valence quarks. A multi-gluon (or sea-quark) transition density is
derived, which shows also breathing, indicating a rather complex multi-quark
structure of N and N* including multi-glue (or q^2n qbar ^-2n) creation out of
the g.s. vacuum.

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The categories of this paper are: physics
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
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The categories of this paper are: comp-gas
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The categories of this paper are: econ
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
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The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-th
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The categories of this paper are: eess