Quantum Electrodynamics (QED) Atoms are composed of unstructured point-like lepton pairs held together by electromagnetic forces.
An artist's impression of a true tauonium. Image credit: Fu other., doi: 10.1016/j.scib.2024.04.003.
“QED atom “Like hydrogen, which is formed from protons and electrons, it is formed from lepton pairs through electromagnetic interactions,” said physicist Jinghan Hu of Peking University and colleagues.
“Their properties have been studied for things like testing QED theory, fundamental symmetries, gravity, and exploring physics beyond the Standard Model.”
“The first QED atom was discovered in 1951. It was in a bonded state and was named positronium.”
“The second one, discovered in 1960, was in a captive state and was named Muonium.”
“No other QED atoms have been discovered in the past 64 years.”
“A new collider is proposed to discover true muonium, which decays to its final state with electrons and photons,” they said.
“The heaviest and smallest QED atoms are tauonium, ditauonium, or true tauonium”
in new paper in a diary science bulletinphysicists introduce a new method to identify true tauonium.
“Tauonium, which consists of tauon and its antiparticle, has a Bohr radius of only 30.4 femtometers, which is about 1/1741 times smaller than the Bohr radius of a hydrogen atom,” the researchers said.
“This means that tauonium can test the fundamental principles of quantum mechanics and QED on a smaller scale, providing a powerful tool for exploring the mysteries of the microscopic world of matter.”
“We will observe taunium by collecting data at 1.5 ab-1, which is close to the threshold for tauon pair production, in an electron-positron collider and selecting signal events containing charged particles accompanied by undetected neutrinos carrying away energy. We have demonstrated that the significance exceeds 5σ.
“This provides strong experimental evidence for the presence of tauonium.”
“We also found that by using the same data, the accuracy of measuring the tau lepton mass can be improved to an unprecedented level of 1 keV, two orders of magnitude higher than the best accuracy achieved in current experiments.”
“This result not only contributes to the accurate verification of the electroweak theory in the Standard Model, but also has profound implications for fundamental physics questions such as the universality of leptonic flavors.”
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Jin Hung Fu other. A new method for determining the heaviest QED atoms. science bulletin, published online on April 4, 2024. doi: 10.1016/j.scib.2024.04.003
Source: www.sci.news
