Dark Matter Annihilation Can Produce a Detectable Antihelium Flux through $\bar{\Lambda}_b$ Decays

Understand

Recent observations by the Alpha Magnetic Spectrometer (AMS-02) have tentatively detected a handful of cosmic-ray antihelium events.

• Such events have long been considered as smoking-gun evidence for new physics, because astrophysical antihelium production is expected to be negligible.
• However, the dark-matter-induced antihelium flux is also expected to fall below current sensitivities, particularly in light of existing antiproton constraints.
• Here, we demonstrate that a previously neglected standard model process -- the production of antihelium through the displaced-vertex decay of $\bar{\Lambda}_b$-baryons -- can significantly boost the dark matter induced antihelium flux.