Tauonium: The Smallest and Heaviest Atom with Pure Electromagnetic Interaction. Credit: © Science China PressRecent discoveries in quantum physics have exposed simpler atomic structures than hydrogen, involving pure electro-magnetic interactions in between particles like electrons and their antiparticles. This advancement has considerable ramifications for our understanding of quantum mechanics and essential physics, highlighted by brand-new approaches for identifying tauonium, which could revolutionize measurements of particle physics.The hydrogen atom was as soon as thought about the easiest atom in nature, made up of a structureless electron and a structured proton. Nevertheless, as research study progressed, researchers discovered a simpler type of atom, consisting of structureless electrons (e– ), muons (μ– ), or tauons (τ–) and their equally structureless antiparticles. These atoms are bound together solely by electro-magnetic interactions, with easier structures than hydrogen atoms, supplying a new perspective on scientific issues such as quantum mechanics, fundamental balance, and gravity.Discovery of Electromagnetic Interaction AtomsTo date, only two kinds of atoms with pure electromagnetic interactions have been found: the electron-positron bound state discovered in 1951 (Phys Rev 1951; 82:455) and the electron-antimuon bound state found in 1960 (Phys Rev Lett 1960; 5:63). Over the past 64 years, there have been no other signs of such atoms with pure electro-magnetic interactions, although there are some proposals to look for them in cosmic rays or high-energy colliders.Tauonium, made up of a tauon and its antiparticle, has a Bohr radius of just 30.4 femtometers (1 femtometer = 10-15 meters), around 1/1741 of the Bohr radius of a hydrogen atom. This indicates that tauonium can test the essential principles of quantum mechanics and quantum electrodynamics at smaller sized scales, providing a powerful tool for exploring the secrets of the micro product world.Recently, a study titled “Novel approach for determining the heaviest QED atom” was released in the comprehensive journal Science Bulletin, proposing a brand-new approach utilized to discover tauonium. The study shows that by collecting information of 1.5 ab-1 near the threshold of tauon pair production at an electron and positron collider, and picking signal events containing charged particles accompanied by the undiscovered neutrinos carrying away energy, the significance of observing tauonium will go beyond 5σ. This suggests a strong speculative evidence for the existence of tauonium.Implications for Fundamental PhysicsThe research study likewise discovered that utilizing the very same information, the accuracy of determining the tau lepton mass can be improved to an extraordinary level of 1 keV, 2 orders of magnitude higher than the highest accuracy attained by present experiments. This achievement will not just contribute to the accurate testing of the electroweak theory in the Standard Model however likewise have extensive implications for basic physics concerns such as lepton taste universality.Future Research DirectionsThis accomplishment works as among the most essential physical objectives of the proposed Super Tau-Charm Facility (STCF) in China or the Super Charm-Tau Factory (SCTF) in Russia: to discover the tiniest and heaviest atom with pure electromagnetic interactions by running the machine near the tauon set limit for one year and to determine the tau lepton mass with a high precision. These discoveries will supply much deeper insights and understanding into humankinds exploration of the tiny world.Reference: “Novel approach for recognizing the heaviest QED atom” by Jing-Hang Fu, Sen Jia, Xing-Yu Zhou, Yu-Jie Zhang, Cheng-Ping Shen and Chang-Zheng Yuan, 4 April 2024, Science Bulletin.DOI: 10.1016/ j.scib.2024.04.003.
