mesons, the positronium is formed by an antielectron (positron) and an electron in a semi-stable arrangement, the protonium
is formed by a proton and an antiproton also semi-stable, the antiprotonic helium is formed by an antiproton and electron together with the helium nucleus (semi-stable), and muonium is formed by a positive muon and an electron.
Physicists in Geneva realized that several years ago they had accidentally combined matter and antimatter into something called protonium
In a second phase, it will study protonium
, a hydrogen-like atom made of a proton and an antiproton.
Another possibility is the making of protonium
, a system in which a proton and an antiproton are bound together and orbit each other.