Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fragmentation, NRQCD and Factorization in Heavy Quarkonium Production   We discuss factorization in heavy quarkonium production in high energy
collisions using NRQCD. Infrared divergences at NNLO are not matched by
conventional NRQCD matrix elements. However, we show that gauge invariance and
factorization require that conventional NRQCD production matrix elements be
modified to include Wilson lines or non-abelian gauge links. With this
modification NRQCD factorization for heavy quarkonium production is restored at
NNLO.

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The categories of this paper are: q-fin
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The categories of this paper are: dg-ga
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
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The categories of this paper are: math-ph
19
The categories of this paper are: eess
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ