Physicists observe antihelium-4 nucleus, the heaviest antinucleus yet
[S]cientists with the STAR collaboration at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory have observed another state of antimatter for the first time: the antimatter helium-4 nucleus, which is the heaviest antinucleus observed so far.
next stop, anti-lithium!
Too bad they didn’t bind a couple of positrons with it.