Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dark Matter's secret liaisons: phenomenology of a dark U(1) sector with
  bound states   Dark matter (DM) charged under a dark U(1) force appears in many extensions
of the Standard Model, and has been invoked to explain anomalies in cosmic-ray
data, as well as a self-interacting DM candidate. In this paper, we perform a
comprehensive phenomenological analysis of such a model, assuming that the DM
abundance arises from the thermal freeze-out of the dark interactions. We
include, for the first time, bound-state effects both in the DM production and
in the indirect detection signals, and quantify their importance for Fermi,
AMS, and CMB experiments. We find that DM in the mass range 1 GeV to 100 TeV,
annihilating into dark photons of MeV to GeV mass, is in conflict with
observations. Instead, DM annihilation into heavier dark photons is viable. We
point out that the late decays of multi-GeV dark photons can produce
significant entropy and thus dilute the DM density. This can lower considerably
the dark coupling needed to obtain the DM abundance, and in turn relax the
existing constraints.

28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci