Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On-shell diagrammatics and the perturbative structure of planar gauge
  theories   We discuss the on-shell diagrammatic representation of theories less special
than maximally supersymmetric Yang-Mills. In particular, we focus on planar
$\mathcal{N}\,\le\,2$ gauge theories, including pure Yang-Mills. For such a
class of theories, the on-shell diagrammatics is endowed with a decoration
which carries the information on the helicity of the coherent states. In the
first part of the paper we extensively discuss the properties of this decorated
diagrammatics. Particular relevance have the helicity flows that the decoration
induces on the diagrams, which allows to identify the different classes of
singularities and, consequentely, the singularity structure of the on-shell
processes. The second part of the paper establishes a link between the
decorated on-shell diagrammatics and the scattering amplitudes for the theories
under examination. We prove that an all-loop recursion relation at integrand
level holds also for $\mathcal{N}\,=\,1,\,2$, while for $\mathcal{N}\,=\,0$ we
are able to set up a preliminary analysis at one loop. In both supersymmetric
and non-supersymmetric case, the treatment of the forward limit is subtle. We
provide a fully on-shell analysis of it which is crucial for the proof of the
all-loop recursion relation and for the analysis of pure Yang-Mills.

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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
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The categories of this paper are: comp-gas
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The categories of this paper are: solv-int
3
The categories of this paper are: physics
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
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The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio