News&Events

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  First Measurement of the Decay Dynamics in the Semileptonic Transition of the D⁺(0) into the Axial-vector Meson K₁(1270) The BESIII collaboration has reported “First Measurement of the Decay Dynamics in the Semileptonic Transition of the D+(0) into the Axial-vector Meson K1(1270)”. These results have been published in Physical Review Letters on 25 August 2025. [Phys. Rev. Lett. 135, 091801 (2025)].
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  Three Resonances in the Cross Section of e⁺ e^-→π⁺ π^- h_c The BESIII collaboration has reported the observation of three resonant structures in the cross section of e+ e-→π+ π- hc based on precise measurements at center-of-mass energies between 4.01 and 4.95 GeV. The cross section exhibits a plateau-like behavior between 4.3 and 4.5 GeV, followed by a sharp drop, revealing for the first time three distinct resonances. These resonances appear at masses of approximately 4.22, 4.33, and 4.47 GeV. The third structure was detected for the first time with a statistical significance exceeding 5σ. The results provide crucial insights into the nature of exotic particles, and have been published in Physical Review Letters on 11 August 2025 [Phys. Rev. Lett. 135, 071901].
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  Precision Measurement of the Branching Fraction of D⁺→μ⁺ν_μ The BESIII collaboration has reported the precision measurement of the branching fraction of the leptonic decay D+→μ+νμ​. This result has been published in Physical Review Letters on 04 August 2025. [Phys. Rev. Lett. 135, 061801 (2025)].
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  Collaboration Meeting in Summer 2025, Jul. 7 - 11, 2025, North China Electric Power University (Beijing, China) The BESIII Collaboration Meeting in Summer of 2025 was held at North China Electric Power University (Beijing Campus) from July 7th to July 11th, 2025.
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  Observation of charmonium h_c radiative decays to multiple light hadrons and the tensor state f₂ (1270) The BESIII Collaboration recently reported “Observation of charmonium hc radiative decays to multiple light hadrons and the tensor state f2 (1270)”. The paper has been published online in Physical Review Letter on June. 17, 2025. [Phys. Rev. Lett. 134, 241902 (2025)].
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  Test of Local Realism via Entangled ΛΛ System The BESIII Collaboration has achieved a landmark violation of Bell inequalities using entangled hyperon pairs, marking a pivotal test of quantum nonlocality in high-energy physics. Published in Nature Communications (Nat. Commun., 16, 4948 (2025)), the study uses (10.087 ± 0.044) × 10⁹ J/ψ events accumulated at BEPCII/BESIII to probe the ΛΛ entangled system produced in J/ψ→ γηc , and ηc → γΛΛ decays.
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  Observation of new modes of Ds decay into Vector-Vector final states ​The BESIII collaboration recently reported the observation of the W-Annihilation Process Ds+→ωρ+ and the measurement of Ds+→ϕρ+. The results have been published in Physics Review Letters on May 22, 2025 [PhysRevLett.134.201902].
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  Observation of the Charmonium Decay η_c→γγ in J/ψ→γη_c The BESIII Collaboration recently reported “Observation of the charmonium decay ηc→γγ in J/ψ→γηc”. The paper has been published online in Physical Review Letters [Phys. Rev. Lett. 134, 181901 (2025)].
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  Observation of an axial-vector state in the decay ψ(3686)→ϕηη' ​The BESIII Collaboration recently reported “Observation of an axial-vector state in the study of the decay ψ(3686)→ϕηη' ”. The paper has been published online in Physical Review Letter. [Phys. Rev. Lett. 134, 191901 (2025)].
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  Special topic on the 50th Anniversary of the Discovery of the Charm Quark and the BESIII Experiment  (in Chinese) 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)