纪念粲夸克发现50周年和北京谱仪III实验专题Special topic on the 50th Anniversary of the Discovery of the Charm Quark and the BESIII Experiment  (in Chinese)第3期—纪念粲夸克发现50周年及北京谱仪Ⅲ实验专题 （全文）      1.  主题导读      2.  粲量子数的诞生      3.  粲夸克的实验发现      4.  Jpsi衰变中轻强子物理探秘      5.  一对重夸克，一类新物质

The BESIII collaboration has reported the observation of D+→η' μ+νμ and first experimental study of D+→η' l+νl decay dynamics. These results have been published in Physical Review Letters on 18 March 2025. [Phys. Rev. Lett. 134, 111801 (2025)].Semileptonic D decays can provide a unique insight for understanding the decay mechanisms of charm quark. In the Standard Model, the semilept...

The BESIII Collaboration recently reported “Measurement of the decay Ξ0→Λγ with entangled Ξ0Ξ0 pairs”,which has been published in Science Bulletin [Sci.Bull. 70 (2025) 454-459].Since the discovery of hyperons in the 1950s, their decay properties have attracted great attention.The radiative decay of hyperons involves an intricate interplay of three fundamental interactions. In 1964, Ya...

The BESIII collaboration recently reported “Observation of Λc+→Λa0(980)+ and Evidence for Σ(1380)+ in Λc+→Λπ+η”, which has been published in Physical Review Letters on Jan. 17th, 2025 [Phys. Rev. Lett. 134, 021901 (2025)].At the microscopic level, quarks are bound together by the strong interaction to form hadrons. Besides conventional hadrons (such as mesons and baryons), the quar...

The BESIII Collaboration recently reported the first observation of the Cabibbo-suppressed semi-leptonic decay Λc+ -> ne+ve, which employs a novel neutron reconstruction method based on a machine learning technology of Graph Neural Network (GNN). The result has been published in Nature Communications on January 15th, 2025 [Nat. Commun. 16, 681 (2025)].The semi-leptonic decay of the lightest ...

The BESIII collaboration recently reported the first amplitude analysis and branching fraction measurement of Ds+→π+ π+ π- π0 decays. The results have been published recently in Physics Review Letters on 7th Jan. 2025 [Phys. Rev. Lett. 134, 011904 (2025)].The exploration of charmed-meson D(s)  hadronic decays allows the interplay of short-distance weak-decay matrix elements and long-d...

The BESIII collaboration recently reported a test of Lepton Universality and precise measurement of the Form Factors of D0→K* (892)- μ+ νμ based on 7.93 fb-1 data collected at the center-of-mass energy of 3.773 GeV. The results have been published recently in Physics Review Letters on January 2, 2025 [Phys. Rev. Lett. 134, 011803 (2025)].Semileptonic D decays provide a good opportunity ...