Tauonium (noun, “TAW-oh-nee-um”)
Tauonium is a type of atom that scientists suspect may exist but have not yet spotted. Unlike typical atoms, it would lack protons, neutrons and electrons.
Atoms usually consist of electrons and a nucleus that contains protons and neutrons. (The one exception to this is the hydrogen atom, which has no neutrons). Electrons carry a negative charge. Protons carry a positive charge.
Positive and negative charges attract each other. That force holds a typical atom together. Another force, called strong force, bundles neutrons and protons in a nucleus.
Like a typical atom, tauonium would be made of smaller particles. But it would not have protons and elections. Instead, tauonium would contain particles called tau and anti-tau. A tau is similar to an electron and carries a negative charge. An anti-tau carries a positive charge. Just like in a typical atom, attraction between opposite charges would hold tauonium together. But unlike other atoms, it would not have strong force.
Why do scientists suspect tauonium might exist? Something similar was seen decades ago. In the 1950s, researchers discovered positronium. This is a type of atom that lacks protons and neutrons. It is made of an electron and a positron. Think of a positron as a positively charged electron. A positron is to an electron what an anti-tau is to a tau. Like tauonium, the pull between opposite charges binds this atom together.
Scientists haven’t yet found tauonium. To search for it, they plan to smash particles together that produce tau particles. They hope the process will also produce tauonium.
If it works, they expect the atom to be short-lived. Based on what they know of similar particles, scientists predict that the particles tau and anti-tau will collide. This collision would occur almost at once. And it would destroy the atom an instant after it formed.
Searching for particles as strange as tauonium might sound like fantasy. But this work helps scientists study matter at the tiniest scales.
In a sentence
Scientists have proposed a method for hunting down tauonium atoms.