Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Leptoproduction of J/\psi   I review the status of the extraction of NRQCD color-octet $J/\psi$
production matrix elements. Large theoretical uncertainties in current
extractions from hadroproduction and photoproduction are emphasized.
Leptoproduction of $J/\psi$ is calculated within the NRQCD factorization
formalism. Color-octet contributions dominate the cross section, allowing for a
reliable extraction of $<{\cal O}_8^{J/\psi}(^1S_0)>$ and $<{\cal
O}_8^{J/\psi}(^3P_0)>$. A comparison with preliminary data from the H1
collaboration shows that leading order color-octet mechanisms agree with the
measured total cross section for $Q^2 > 4m_c^2$, while the color-singlet model
underpredicts the cross section by a factor of 5.

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The categories of this paper are: stat
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The categories of this paper are: hep-th
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The categories of this paper are: patt-sol
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The categories of this paper are: gr-qc
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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: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: nlin
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The categories of this paper are: cs
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The categories of this paper are: dg-ga
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The categories of this paper are: supr-con
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: econ
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The categories of this paper are: chao-dyn