How to produce antinuclei from dark matter

We show how to produce antideuteron, antihelium, and other antinuclei in large fractions from the decays of a new particle $\phi$ that carries baryon number. Close to threshold, the production of nuclear bound states is preferred over the decay into individual nucleons, effectively decoupling antinuclei and antiproton fluxes and allowing the former to dominate, in clear contrast to antimatter production via coalescence. $\phi$ can either form dark matter itself or be produced by it, and can give rise to a potentially testable amount of antinuclei.