Recent studies have introduced a new method for the potential discovery of a particle type called Tauonium, consisting of tauons and antitauons. This particle presents an opportunity to test quantum mechanics and quantum electrodynamics on smaller scales, potentially yielding significant insights into fundamental physics issues. The findings of this research also align with the primary goals of facilities like STCF in China or SCTF in Russia.
Tauonium-Pure-Electromagnetically-Interactive-Cephe-Hercules
Once considered the simplest atom in nature, hydrogen,
composed of an electron and fundamental particles like protons, has evolved
with discoveries of simpler atom types comprising electrons, muons, or tauons
and their corresponding antiparticles. These atoms, held together solely by electromagnetic
interactions and having simpler structures than hydrogen atoms, offer new
perspectives on scientific problems such as quantum mechanics, fundamental symmetries, and gravity.
The discovery of bound states like electron-positron and electron-antimuon in 1951 and 1960
respectively, represented the only two types of atoms found to have pure electromagnetic
interactions. For the past 64 years, no further clues had been found regarding
atoms with such interactions, although some researchers suggested looking for
them in cosmic rays or high-energy colliders.
Tauonium, composed of a tauon and its antiparticle, has a Bohr
radius of only 30.4 femtometers (1 femtometer = 10^-15 meters), approximately 1/1,741
of the Bohr radius of a hydrogen atom. These properties of Tauonium indicate
its potential to test the fundamental laws of quantum mechanics and quantum
electrodynamics on smaller scales, making it an effective tool for exploring
the mysteries of the micro-matter universe.
A recent study published in Science Bulletin, titled "A New Method for Identifying the
Heaviest QED Atom," proposed a new strategy for the discovery of Tauonium.
The study collected data close to the production threshold of tauon pairs in an
electron-positron collider, selecting signal events containing charged particles
accompanied by undetected neutrinos. The observation of Tauonium exceeded a
significance level of 5σ, providing strong experimental evidence for its
existence.
Furthermore, the study revealed that using the same data,
the sensitivity to detecting the tau lepton mass could be increased to an
unprecedented level of 1 keV, twice the maximum sensitivity obtained with
current studies. This achievement will not only assist in confirming the electro-weak
theory in the Standard Model but may also lead to comprehensive results for
fundamental physics issues such as lepton flavor universality.
This success aligns with the primary physical goals of
proposed facilities like the Super Tau-Charm Facility (STCF) in China or the Super Charm-Tau Factory (SCTF) in
Russia: to operate the machine close to the threshold of tauon pairs for a year
and measure the tau lepton mass with high precision, ultimately discovering the
smallest and heaviest atom with pure electromagnetic interactions.