Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Three-Quark Bethe-Salpeter Vertex Function Under Pairwise
  Gluon-Exchange-Like Interaction : Application to n-p Mass Difference   A qqq BSE formalism based on an input 4-fermion Lagrangian of `current' u,d
quarks, is employed for the construction of a relativistic qqq-wave function)
via the BSE. Chiral invariance is ensured by the vector character of the
gluonic propagator in the infrared regime, while the `constituent' masses are
the low momentum limits of the dynamicalmass function generated by standard
DB{\chi}. The Covariant Instantaneity Ansatz (CIA) gives an exact 3D reduction
of the BSE for baryon spectroscopy, while the reconstructed 4D form identifies
the baryon quark vertex function reconstructed through a reversal of steps
offered by the CIA structure. It is employed for the quark loop integrals for
the neutron - proton mass difference which receives contributions from two
sources : i) the strong SU(2) effect arising from the $u-d$ mass difference (4
MeV); ii) the e.m. effect of the respective quark charges. The resultant n-p
difference works out at 1.28 MeV (vs. 1.29 expt), with only two free parameters
characterizing the infrared structure of the gluonic propagator, precalibrated
via a common fit to meson and baryonspectra plus several other observable
amplitudes. (PACS : 11.10 st ; 12.35 Ht ; 12.70 + q)

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The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas
1
The categories of this paper are: cs
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The categories of this paper are: math-ph
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
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The categories of this paper are: astro-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
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The categories of this paper are: chem-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: q-bio