講座主題：Heavy-flavor-conserving weak decays of heavy baryons
專家姓名：鄭海揚
工作單位：中國臺灣中研院物理所
講座時間：2024年04月17日14:30-16:00
講座地點：科技館1511會議室
主辦單位：煙臺大學物理與電子信息學院
內容摘要：
Three decades ago, heavy-flavor-conserving (HFC) weak decays of heavy baryons such as ΞQ→ΛQ+π and ΩQ→ΞQ+π for Q = c, b had been proposed and studied within the framework that incorporates both heavy-quark and chiral symmetries. HFC decays have two great advantages: (1) S-wave can be evaluated reliably using current algebra, and (2) if the heavy quark in the HFC process behaves as a spectator, then the P-wave amplitude of ΞQ→ΛQ+π will vanish. In the b sector, HFC decay was first measured by LHCb in 2014 and it was well understood. However, HFC decay in the charm sector, namely, ΞQ→ΛQ+π was not measured until 2020. The theoretical prediction of its branching fraction is too small compared to experiment. The puzzle was finally resolved recently. It took thirty years to fully understand the underlying mechanism forcharm-flavor-conserving weak decays of charmed baryons.
主講人介紹：
鄭海揚，中國臺灣中研院物理研究所特聘研究員。1980年獲得美國普渡大學物理學博士學位，1980至1985期間，在普渡大學和布蘭迪斯大學從事博士后研究，1988年任中國臺灣中研院全職研究員，2012年起任特聘研究員。先后在普渡大學、印第安納大學、紐約州立大學石溪分校、布魯克海汶國家實驗室任訪問教授。鄭海揚研究員多年來一直致力于重味物理、強子物理領域的學術研究，做了許多先驅性的工作，在國際上享有盛譽。迄今為止，在Phys.Rev.Lett.、Phys.Rev.D等主流期刊發表論文240余篇，引用16000余次，單篇引用超100次以上文章30余篇，h因子68。
