A new study puts upper bounds on the cross-section of interaction of dark matter particles at masses up to 100,000 GeV (i.e. up to masses about a hundred times greater than the masses that can be probed with direct dark matter detectors and particle accelerators), based upon observations from the vicinity of the Milky Way's central black hole, under various assumptions, including the not very well justified assumption that the dark matter particle can annihilate.
The limits at lower masses aren't nearly as stringent of those from existing experiments, and the limits at higher masses still don't rule out cross-sections of interaction as strong as those of neutrinos. But these are some of the strongest constraints to date for hypothetical dark matter particles with masses from 1,000 to 100,000 GeV.
Of course, for a variety of reasons that I won't reiterate in this post, in all likelihood, the phenomena attributed to dark matter have a gravitational cause of some kind, and are not actually due to the gravitational pull of dark matter particles of the type tested for in this paper.
We use H.E.S.S. γ-ray observations of Sgr A* to derive novel limits on the Dark Matter (DM) annihilation cross-section.
We quantify their dependence on uncertainties i) in the DM halo profile, which we vary from peaked to cored, and ii) in the shape of the DM spike around Sgr A*, dynamically heated by the nuclear star cluster. For peaked halo profiles and depending on the heating of the spike, our limits are the strongest existing ones for DM masses above a few TeV. Our study contributes to assessing the influence of the advancements in our knowledge of the Milky Way on determining the properties of DM particles.
Shyam Balaji, Divya Sachdeva, Filippo Sala, Joseph Silk, "Dark Matter spikes around Sgr A* in γ-rays" arXiv:2303.12107 (March 21, 2023).
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