Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dark Matter bound-state formation at higher order: a non-equilibrium
  quantum field theory approach   The formation of meta-stable dark matter bound states in coannihilating
scenarios could efficiently occur through the scattering with a variety of
Standard Model bath particles, where light bosons during the electroweak cross
over or even massless photons and gluons are exchanged in the t-channel. The
amplitudes for those higher-order processes, however, are divergent in the
collinear direction of the in- and out-going bath particles if the mediator is
massless. To address the issue of collinear divergences, we derive the
bound-state formation collision term in the framework of non-equilibrium
quantum field theory. The main result is an expression for a more general cross
section, which allows to compute higher-order bound-state formation processes
inside the primordial plasma background in a comprehensive manner. Based on
this result, we show that next-to-leading order contributions, including the
bath-particle scattering, are i) collinear finite and ii) generically dominate
over the on-shell emission for temperatures larger than the absolute value of
the binding energy. Based on a simplified model, we demonstrate that the impact
of these new effects on the thermal relic abundance is significant enough to
make it worthwhile to study more realistic coannihilation scenarios.

9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg