limits on dark matter by ANTARES from searches in the Galactic Centre
and the Earth
One of the most relevant physics topics
studied by ANTARES is the nature of dark matter. Weakly Interacting
Massive Particles (WIMPs) are the most popular set of candidates. If they
are their own anti-particles, we could see the products of their
annihilations, among them neutrinos. There are several astrophysical
sources interesting to look for dark matter with neutrino telescopes,
which can be broadly classified in two categories. In the Sun or the
Earth, the accumulation of dark matter occurs after WIMPs are scattered by
nuclei and become gravitationally trapped. In other sources like the
Galactic Centre, dwarf galaxies and galaxy clusters, the accumulation is
produced along the process of structure formation. In the former case, the
observations on the neutrino flux are translated into WIMP-nucleon
scattering cross sections, whereas in the latter case they give us
information about WIMP annihilation cross sections.
The ANTARES collaboration has recently made public the results of two
searches for dark matter: one in the Galactic Centre 
and another in the Earth 
which complement or expand previous results (Sun 
, and Galactic Centre 
The new results on the Galactic Centre show the potential of neutrino
telescopes, and of those in the Mediterranean in particular, in the search
for dark matter. As it can be seen in Figure 1, the new limits, which use
data from 2007 to 2015, are below those set by IceCube along almost the
whole range of masses studied. This improvement comes from the fact that
the Galactic Center is better visible from the Northern Hemisphere, since
it allows to use the Earth as a filter against the background from
atmospheric muons, and the better angular resolution attainable in water.
It can also be seen that ANTARES limits are below any other experiment for
masses above 30 TeV.
Figure 1 - Limits on the WIMP annihilation cross section for
ANTARES with 2007-2015 data, compared with other experiments. The
results from neutrino telescopes. See 
for more details.
The results of the search for neutrinos produced after the WIMP
annihilations in the Earth are shown in Figure 2. For neutrino telescopes,
the most interesting case corresponds to masses of the WIMP close to the
mass of the Earth’s core nuclei (iron, in particular), since the capture
is enhanced, and for spin-independent cross section. The results are not
as constraining as those set by direct searches but are also relevant
since different systematic uncertainties apply.
Figure 2 - Limits on the spin independent WIMP-nucleon scattering
cross section for ANTARES using 2007-2012 data, compared to other
experiments. See 
for more details.
These results show the potential of neutrino telescopes as a tool for
particle physics in addition to their use for neutrino astronomy. This
potential will be largely increased with the completion of the successor
of ANTARES: KM3NeT, which is already in construction.