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Title: Is there an antiproton excess near 10 to 20 GeV?
Plain: Some analyses of space-station data found slightly more antiprotons near 10 to 20 GeV than expected, which could come from dark matter particles annihilating. Others find the excess disappears when measurement errors and production rates are treated more carefully.
Precise: Decide whether the AMS-02 antiproton-to-proton ratio shows a statistically significant excess at rigidities of about 10 to 20 GV over secondary production, once correlated systematic errors, antiproton production cross-section uncertainties and solar modulation are included. A significant excess has been fit by dark matter of mass about 50 to 80 GeV annihilating to b-bbar.
Settled by: Published AMS-02 correlation matrices plus new accelerator measurements of p-p and p-He antiproton production at the relevant energies.
Kind: well-posed
Answer type: yes-no
References: (empty)
Literature status: contested
Status note: Analyses including correlated errors reduced the significance below about $2\sigma$, and 2025 studies of solar modulation (Duan et al., JCAP, 2025) have not produced a consensus.
Posed since: 2016