Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectral representation for u- and t-channel exchange processes in a
  partial-wave decomposition   We study the analytic structure of partial-wave amplitudes derived from u-
and t-channel exchange processes. The latter plays a crucial role in
dispersion-theory approaches to coupled-channel systems that model final state
interactions in QCD. A general spectral representation is established that is
valid in the presence of anomalous thresholds, decaying particles or
overlapping left-hand and right-hand cut structures as it occurs frequently in
hadron physics. The results are exemplified at hand of ten specific processes.

1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol