Project Description
The nature of dark matter remains one of the most pressing open questions of modern physics. Since the mass of the dark-matter particle is unknown and collider experiments will not be able to probe the PeV regime directly in the foreseeable future, indirect searches with cosmic messengers are among the most sensitive ways to detect very heavy dark-matter particles or to constrain their properties. So far, searches at these energies have been comparatively limited in scope. Project F8 is a pathfinder for indirect dark-matter searches at the highest photon energies currently accessible to observations. It complements the searches for Weakly Interacting Massive Particles (WIMPs) at the electroweak mass scale and for light axion-like particles carried out in project F5. New instruments for the energy range above a few TeV, namely the Cherenkov Telescope Array Observatory (CTAO), Dark100 and the planned Southern Wide-field Gamma-ray Observatory (SWGO), are about to open this window, and the project leaders are members of these collaborations. Within this project we will focus on the following goals:
- Shaping observational programmes and carrying out some of the most sensitive searches to date for ultra-heavy dark matter, targeting the central region of the Milky Way and candidate dwarf galaxies in the Galactic halo identified in project F5;
- Characterising the cosmic-ray proton background at the high-energy frontier and improving the observational sensitivity with tuned Monte Carlo simulations from projects F3 and F4;
- Laying the groundwork for a joint, multi-instrument dark-matter analysis spanning TeV to PeV energies.
The project is closely connected to project F5 (selection of targets, transfer of analysis methods), to projects A1 and A2 (astrophysical backgrounds from the Galactic disc and from dwarf galaxies), and to project F4, to which we provide very-high-energy observations of the Crab Nebula as test data sets. As the newly accessible photon energies overlap with the energy range covered by neutrino telescopes such as IceCube, multimessenger connections will be explored as well. The timing is ideal: during Phase 2 of CIM, the first data from the new telescopes above a few TeV become available. Together with F5, the project will establish a comprehensive picture of dark-matter limits from sub-TeV energies to beyond 1 PeV.
