Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Threshold expansion of Feynman diagrams within a configuration space
  technique   The near threshold expansion of generalized sunset-type (water melon)
diagrams with arbitrary masses is constructed by using a configuration space
technique. We present analytical expressions for the expansion of the spectral
density near threshold and compare it with the exact expression obtained
earlier using the method of the Hankel transform. We formulate a generalized
threshold expansion with partial resummation of the small mass corrections for
the strongly asymmetric case where one particle in the intermediate state is
much lighter than the others.

36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph