摘要：

The bound state of two tau leptons, ditauonium, is the heaviest and also most compact atom predicted purely by QED. There are several motivations to study it (such as the properties of tau lepton, the precision tests of SM and basic symmetries, and its sensitivities to BSM effects). In this talk, I will first discuss the spectroscopy of ditauonium, including the energy levels and decay channels. Then, I will present a survey of the possible searches at present and future colliders. In particular, I will highlight the discovery potential of the spin-triplet state, ortho-ditauonium, at a future super tau-charm factory (STCF). Finally, I will show that with monochromatized beams, the observation of ortho-ditauonium can provide a very precise extraction of the tau lepton mass at STCF.

References: 2202.02316, 2204.07269. 2302.07365

报告人简介：

Hua-Sheng Shao is a permanent CNRS researcher in Paris (LPTHE in Sorbonne University) since 2017. Before that, he was a postdoc at CERN (2014-2017) and a PhD student in Peking University (2009-2014). His research interests are, generally speaking, the theoretical and phenomenological aspects in particle physics. More specifically, he has worked on the collider (e.g., LHC) physics mainly in SM and partially in BSM.