Antideuterons and antihelium nuclei from annihilating dark matter

Journal Article · Mon Nov 16 00:00:00 UTC 2020 · Physical Review. D.

DOI: https://doi.org/10.1103/physrevd.102.103019 · OSTI ID:1597058

Cholis, Ilias  ^[1]; Linden, Tim  ^[2]; Hooper, Dan  ^[3]

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1. Oakland Univ., Rochester, MI (United States)
2. Stockholm Univ. (Sweden); Oskar Klein Centre, Stockholm (Sweden); The Ohio State Univ., Columbus, OH (United States)
3. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, IL (United States)

Recent studies of the cosmic-ray antiproton-to-proton ratio have identified an excess of ~10–20 GeV antiprotons relative to the predictions of standard astrophysical models. Intriguingly, the properties of this excess are consistent with the same range of dark matter models that can account for the long-standing excess of γ-rays observed from the Galactic Center. Such dark matter candidates can also produce significant fluxes of antideuterium and antihelium nuclei. In this work we study the production and transport of such particles, both from astrophysical processes as well as from dark matter annihilation. Importantly, in the case of AMS-02, we find that Alfvénic reacceleration (i.e., diffusion in momentum space) can boost the expected number of $$\bar {\text d}$$ and $$^ {\text 3} \overline {\text {He}}$$ events from annihilating dark matter by an order of magnitude or more. For relatively large values of the Alfvén speed, and for dark matter candidates that are capable of producing the antiproton and γ-ray excesses, we expect annihilations to produce a few antideuteron events and about one antihelium event in 6 yr of AMS-02 data. This is particularly interesting in light of recent reports from the AMS-02 Collaboration describing the detection of a number of antihelium candidate events.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: European Research Council (ERC); Swedish National Space Agency (SNSA); Swedish Research Council (VR); USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: AC02-07CH11359; SC0009924
• OSTI ID: 1597058
• Report Number(s): FERMILAB-PUB--20-021-A; arXiv:2001.08749; oai:inspirehep.net:1777142
• Journal Information: Physical Review. D., Journal Name: Physical Review. D. Journal Issue: 10 Vol. 102; ISSN 2470-0010
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English