Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Rotational covariance and light-front current matrix elements   Light-front current matrix elements for elastic scattering from hadrons with
spin~1 or greater must satisfy a nontrivial constraint associated with the
requirement of rotational covariance for the current operator. Using a model
$\rho$ meson as a prototype for hadronic quark models, this constraint and its
implications are studied at both low and high momentum transfers. In the
kinematic region appropriate for asymptotic QCD, helicity rules, together with
the rotational covariance condition, yield an additional relation between the
light-front current matrix elements.

5
The categories of this paper are: gr-qc
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The categories of this paper are: cond-mat
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The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
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The categories of this paper are: funct-an
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The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: quant-ph
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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom