Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polarization observables for elastic electron scattering off a moving
  nucleon   General expressions for all parity-conserving polarization observables of
elastic electron-nucleon scattering in the one-photon exchange approximation
are derived for a general frame of reference, i.e.\ not assumming scattering
off a nucleon at rest and not specializing to a specific system of coordinates.
Essentially, the given expressions are also valid for the inverse process,
i.e.\ nucleon scattering off electrons.

17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
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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: patt-sol
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The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc