Talk of the tauonium
Scientists propose a hunt for tauonium, a hypothetical variety of atom that would consist of a tau lepton and its antimatter counterpart, an antitau, Emily Conover reported in “Tauonium” (SN: 6/29/24, p. 5).
Reader Hal Heaton asked why tauonium would be classified as an atom, considering it wouldn’t have typical atomic features: electrons and a nucleus of protons and neutrons.
Tauonium would be part of a class called exotic atoms, Conover says. These are similar to the standard atoms on the periodic table but with at least one constituent replaced by another particle. For example, an electron can be replaced with a heavier relative, such as a muon. Or a neutron can be replaced with another particle, such as a hyperon, which contains a strange quark.
In the case of tauonium, a hydrogen atom’s electron is replaced with a negatively charged tau lepton, and its proton is replaced with a positively charged antitau, Conover says.
Reader Guy DeWhitney asked why the article states that scientists want to “search” for tauonium. “Create” or “invent” seem to be more appropriate descriptions, DeWhitney says.
It’s true that tauonium would be created in the process that scientists propose. But “invented” is not quite accurate. Theoretical physicists previously came up with the concept of tauonium, as well as a description for how the atom would behave, Conover says.
Several readers wondered how stable tauonium would be.
Tauonium would likely decay very quickly, says physicist Yu-Jie Zhang of Beihang University in Beijing. Its estimated average lifetime is about 20 quadrillionths of a second.
The atom’s tau and antitau particles would orbit one another briefly before eventually colliding and annihilating one another, releasing energy in the process, Conover says.
