News&Events

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  BESIII Physics and Software Workshop in Autumn 2026，Shandong University of Technology (Zibo, China) The BESIII Physics & Software workshop in Autumn 2026 was held during Sep. 14-17th at Shandong University of Technology (Zibo, China).
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  BESIII Achieves World's Most Precise Measurement of Lambda Hyperon Electric Dipole Moment The BESIII Collaboration has achieved the world's most precise measurement of the electric dipole moment (EDM) of the Lambda (Λ) hyperon using quantum-entangled Λ–anti-Λ pairs produced in J/ψ decays. The result improves the experimental sensitivity by about three orders of magnitude compared with the previous measurement, providing a new way to probe charge-parity (CP) violation in particles containing strange quarks.
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  BESIII Observes Transverse Polarization of Charmed Baryons for the First Time he BESIII Collaboration has observed, for the first time, transverse polarization of the lightest charmed baryon, the Λ₊⁺, produced in electron-positron annihilation near the production threshold. The study also provides a systematic investigation of the production and weak-decay dynamics of the Λ₊⁺. The results have been published in Physical Review X under the title "Production and Decay Dynamics of the Charmed Baryon Λ₊⁺ in e⁺ e⁻ Annihilations near Threshold." This marks the first publication by the BESIII Collaboration in Physical Review X.
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  Quantum-entangled hyperons open a new route to testing the Standard Model BESIII pioneers a study of baryon semileptonic decays through polarization and quantum entanglement, including the first semileptonic form-factor measurements for an antihyperon.
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  First observation of D⁰⁽⁺⁾ → K̅ ω e⁺ νₑ decays and experimental evidence for the two-pole structure of K̅₁(1270)
  
  The BESIII collaboration recently reported the first observation of the semileptonic decays D⁰ → K⁻ ω e⁺ νₑ and D⁺ → K_S⁰ ω e⁺ νₑ with significances of 8.0σ and 5.8σ, respectively. The measurement is based on 20.3 fb⁻¹ of e⁺ e⁻ annihilation data collected at a center-of-mass energy of 3.773 GeV. This work provides the most precise measurement of the branching fraction (BF) of K̅₁(1270) → K̅ ω decay from a collider experiment to date, and offers unique experimental evidence for the two-pole structure of the K̅₁(1270) resonance. The results have been published recently in Physical Review Letters on 26 August, 2026 [Phys. Rev. Lett. 137, 091802].
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  First Experimental Constraint on the Scalar Current and Precise measurements of D⁰⁽⁺⁾ → K̅ l⁺ νₗ decays The BESIII collaboration has reported "First Experimental Constraint on the Scalar Current in the D⁰⁽⁺⁾ → K̅ l⁺ νₗ Transition" and "Precise measurements of D⁰ → K⁻ l⁺ νₗ and D⁺ → K̅⁰ l⁺ νₗ decays". These results have been published in Physical Review Letters [Phys. Rev. Lett. 137, 091803 (2026)], accompanied by a detailed companion paper in Physical Review D [Phys. Rev. D. 114, 033008 (2026)] on 27 Aug 2026.
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  The first measurement of the semileptonic decay Ξ⁻ → Λ e⁻ νbar_e at an electron-positron collider The BESIII Collaboration has reported the first measurement of the semileptonic decay Ξ⁻ → Λ e⁻ νbare at an electron-positron collider, providing the first determination of its absolute branching fraction, as well as the first update of the Ξ⁻ axial charge in more than four decades. The result has been published in Physical Review Letters [Phys. Rev. Lett. 137, 091801 (2026)].
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  BESIII Experiment Identifies X(2370) as a Glueball-dominated Particle At the International Conference on High Energy Physics held in Brazil, the BESIII Collaboration at the Beijing Electron Positron Collider announced in a special plenary report that after fifteen years of sustained research, the BESIII Collaboration identified that the dominant constituent of the X(2370) is a pseudoscalar glueball with spin-parity quantum numbers of 0⁻⁺.
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  BESIII Sets New Bound for Sub-GeV Dark Matter Interactions The BESIII Collaboration recently reports the search for sub-GeV dark particles in η→π⁰+invisible decay and provides a new bound for the sub-GeV dark matter, which has been published in Physical Review Letters on 16th July, 2026 [Phys. Rev. Lett. 137, 031804] as PRL Editors Suggestion.
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  BESIII Reports First Measurements of Antineutron–Proton Annihilation into Multi-Pion Final States Recently, the BESIII collaboration has reported new results on antineutron–proton interactions by measuring the annihilation processes n̄ p → 2 π+ π-, n̄ p → 2 π+ π- π0, and n̄ p → 2 π+ π- 2 π0. The results have been published in Physical Review Letters (Phys. Rev. Lett. 137, 031902 (2026)).