报告人:淦丽萍 教授 (University of North Carolina Wilmington) 报告时间:2022年07月22日 10:00 - 11:30 (Beijing time) 摘要: The confinement nature of Quantum Chromodynamics (QCD) and the new physics Beyond the Standard Model (BSM) are two frontiers in contemporary science. The system of η and η′ offers a rich laboratory to explore both fundamental issues. The symmetries of QCD at low energies are manifested in the most unambiguous form in η and η′. Precision measurements of their properties will yield light on our understanding of the QCD symmetry structure, as well as the origin and dynamics of the confinement. In addition, the η(′) meson has quantum numbers of vacuum (except parity) with its strong and electromagnetic decays being either anomalous or forbidden to the lowest order due to symmetries or angular momentum conservation. This enhances the relative importance of higher order contributions, making the rare η(′) decays a sensitive hadronic probe for weakly-coupled new forces. Searching for sub-GeV dark gauge bosons, and C-violating, P-conserving interactions in various η(′)decays will extend our knowledge of the dark sector and explore new sources of CP violation that is needed to explain the observed matter and anti-matter asymmetry in the universe. This talk will give an overview of the current status and the future experimental opportunities in the η(′) physics. 报告人简介: Prof. Liping Gan is a full professor at University of North Carolina Wilmington, NC, USA. She received Ph.D. in University of Manitoba, Canada, and M.S. and B.S. in Peking University, China. Her researches focus on the confinement QCD and new physics beyond the standard model via precision measurement of the light meson decays. Prof. Gan is a leader and a spokesperson for three experiments at Jefferson Lab: (1) the PrimEx-IIexperiment in Hall B (E-08-023), carried out the most precise measurement of the π0 lifetime published up to date; (2) the PrimEx-eta experiment, a measurement of the η radiative decay width in Hall D (E-10-011); (3) the JLab Eta factory (JEF) experiment (E12-12-002A), a study of η/η′ decays with emphasis on rare modes in Hall D.