Today we publish the first limits on the interaction of antiprotons with axion-like dark matter. For this work we’ve teamed up with scientists from the PRISMA+ cluster at Mainz, which have great expertise in dark matter research

Astronomical observations tell us that dark matter makes up most of the matter in the cosmos but we do not know what it is made of. Additionally, theories of the early universe predict that both antimatter and matter should have been produced in equal amounts, yet for some reason matter prevailed. Could there be a relation between matter–antimatter asymmetry and dark matter?

To investigate that question, we’ve performed the first explicit laboratory search for an interaction between antimatter and axion-like particles. Using the two particle/three trap method invented by BASE we’ve measured the antiproton magnetic moment with a fractional precision of 1.5 parts in a billion. We’ve analyzed the resulting g-factor resonance for oscillatory signatures which –would be induced by dark matter interactions. This type of data treatment enabled us to extract the first direct limits on the coupling between axion like particles and antiprotons.

Our analysis constrains the axion–antiproton interaction parameter to values greater than 0.1 to 0.6 GeV in the mass range from 2 × 10-23 to 4 × 10-17 eV, improving the sensitivity by up to five orders of magnitude compared with astrophysical antiproton bounds. In addition, we derive limits on six combinations of previously unconstrained Lorentz- and CPT-violating terms of the non-minimal standard model extension.

Secondary Articles:

CERN: https://home.cern/news/news/physics/probing-dark-matter-using-antimatter

Nature News and Views: https://www.nature.com/articles/d41586-019-03431-5