Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two-loop divergences of massive scattering amplitudes in non-abelian
  gauge theories   The infrared divergences of QCD scattering amplitudes can be derived from an
anomalous dimension \Gamma, which is a matrix in color space and depends on the
momenta and masses of the external partons. It has recently been shown that in
cases where there are at least two massive partons involved in the scattering
process, starting at two-loop order \Gamma receives contributions involving
color and momentum correlations between three (and more) partons. The
three-parton correlations can be described by two universal functions F_1 and
f_2. In this paper these functions are calculated at two-loop order in closed
analytic form and their properties are studied in detail. Both functions are
found to be suppressed like O(m^4/s^2) in the limit of small parton masses, in
accordance with mass factorization theorems proposed in the literature. On the
other hand, both functions are O(1) and even diverge logarithmically near the
threshold for pair production of two heavy particles. As an application, we
calculate the infrared poles in the q qbar --> t tbar and g g --> t tbar
scattering amplitudes at two-loop order.

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The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom