Physicists from the STAR Collaboration have observed the antimatter hypernucleus antihyperhydrogen-4 — composed of an antihyperon, an antiproton and two antineutrons — in collisions of atomic nuclei at the Relativistic Heavy Ion Collider (RHIC) at DOE’s Brookhaven National Laboratory. An artistic representation of antihyperhydrogen-4 created in a collision of two gold nuclei. Image credit: Institute of Modern Physics. “Our physics...