Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin Filter in DVCS amplitudes   In deeply virtual Compton scattering (DVCS) it is found that in some
kinematics angular momentum is not conserved if the amplitudes are calculated
in terms of widely used reduced operators. Consequently, those kinematics will
lead to the wrong analysis of experimental data in terms of generalized parton
distributions. Contrary to common lore, the contribution of the longitudinally
polarized virtual photon should not be neglected in the analysis of DVCS
amplitudes.

14
The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
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The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
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The categories of this paper are: dg-ga
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The categories of this paper are: quant-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: astro-ph
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The categories of this paper are: nlin
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The categories of this paper are: nucl-ex
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The categories of this paper are: cond-mat
1
The categories of this paper are: cs
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The categories of this paper are: chem-ph