Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Revisiting the factorization theorem for $\rho \gamma^{*} \to \pi(\rho)$
  at twist 3   We revisit the proof of the perturbative QCD factorization for the exclusive
processes $\rho \gamma^{\star} \to \pi(\rho)$ at the two-parton twist-3 level.
It is pointed out that the residual collinear divergences observed in the
literature, which break the factorization of the above processes at the
considered accuracy, are attributed to the improper insertion of the Fierz
identity for factorizing the fermion flow. We show that the factorization
theorem indeed holds at the two-parton twist-3 level after the mishandling is
corrected.

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The categories of this paper are: q-bio
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The categories of this paper are: plasm-ph
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The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: quant-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: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: astro-ph
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The categories of this paper are: supr-con
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The categories of this paper are: math-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: hep-th