Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Massive Quark-Gluon Scattering Amplitudes at Tree Level   Results for four-, five-, and six-parton tree amplitudes for massive
quark-antiquark scattering with gluons are calculated using the recursion
relations of Britto, Cachazo, Feng, and Witten. The required diagrams are
generated using shifts of the momenta of a pair of massless legs to complex
values. Checks verifying the calculations are described, and a simple formula
for the shifted spinors of an internal gluon is presented.

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The categories of this paper are: comp-gas
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The categories of this paper are: stat
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The categories of this paper are: adap-org
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The categories of this paper are: chem-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: cs
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The categories of this paper are: plasm-ph
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The categories of this paper are: math
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th
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The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: q-bio