Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Leptoproduction of J/psi   We study leptoproduction of $J/\psi$ at large $Q^2$ within the
nonrelativistic QCD (NRQCD) factorization formalism. The cross section is
dominated by color-octet terms that are of order $\alpha_s$. The color-singlet
term, which is of order $\alpha^2_s$, is shown to be a small contribution to
the total cross section. We also calculate the tree diagrams for color-octet
production at order $\alpha^2_s$ in a region of phase space where there is no
leading color-octet contribution. We find that in this regime the color-singlet
contribution dominates. We argue that non-perturbative corrections arising from
diffractive leptoproduction, higher twist effects, and higher order terms in
the NRQCD velocity expansion should be suppressed as $Q^2$ is increased.
Therefore, the color-octet matrix elements $< {\cal O}_8^{\psi}(^1S_0)>$ and
$<{\cal O}_8^{\psi}(^3P_0)>$ can be reliably extracted from this process.
Finally, we point out that an experimental measurement of the polarization of
leptoproduced $J/\psi$ will provide an excellent test of the NRQCD
factorization formalism.

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The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
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The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci