Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin Observables in Coincidence Electron Scattering from Nuclei I:
  Reduced Response Functions   A theoretical description of nucleon knockout reactions initiated by
polarized electron scattering from polarized nuclei is presented. Explicit
expressions for the complete set of reduced response functions (independent of
the polarization angle) that can be experimentally obtained assuming plane
waves for the electron are given in a general multipole expansion. The
formalism is applied to the particular case of closed-shell-minus-one nuclei
using two models for the ejected nucleon, including the final-state interaction
phenomenologically with a complex optical potential and in the factorized
plane-wave impulse approximation. Relativistic effects in the kinematics and in
the electromagnetic current are incorporated throughout --- specifically a new
expansion of the electromagnetic current in powers only of the struck nucleon
momentum is employed. Results are presented for the nucleus 39K.

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The categories of this paper are: math-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: adap-org
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The categories of this paper are: chao-dyn
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The categories of this paper are: mtrl-th
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: eess
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The categories of this paper are: nucl-ex
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The categories of this paper are: cond-mat
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The categories of this paper are: q-bio
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The categories of this paper are: physics
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The categories of this paper are: gr-qc
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The categories of this paper are: quant-ph