# BESIII confirms evidence of glueball particle X(2370)

> Live situation record from CLSTR: https://clstr.news/situations/besiii-glueball-particle-discovery
> Updated: 2026-09-03T06:45:00.000Z. Sources: 14. Developments: 4.

Researchers from the Beijing Spectrometer III (BESIII) collaboration, part of the Institute of High Energy Physics under the Chinese Academy of Sciences, have announced findings providing the first definitive experimental evidence of a glueball. By analyzing more than ten billion decays of the J/ψ particle at the Beijing Electron-Positron Collider II, the team identified the X(2370) particle.

The findings, presented at the International Conference on High Energy Physics (ICHEP) in Brazil, indicate that the particle’s mass, quantum numbers, and flavor-singlet nature align with theoretical predictions for a pseudoscalar glueball. This discovery, achieved after 15 to 17 years of data collection, marks the most compelling evidence for glueballs in half a century of searches and validates long-standing predictions of quantum chromodynamics (QCD). The identification provides a fundamental verification of the non-Abelian gauge structure of QCD at low energies.

While the results suggest the X(2370) is a composite particle made entirely of gluons, researchers intend to conduct further decay measurements. These future studies aim to determine the extent of any mixing between the glueball and ordinary quark matter. In a related development, the BESIII collaboration also utilized quantum entanglement with antimatter to perform a decay measurement of the lambda hyperon, yielding results that align with conventional theoretical predictions but stand in tension with previous measurements.

## Timeline

### 2026-09-03: BESIII collaboration identifies glueball matter and advances particle physics

The BESIII collaboration has identified glueballs, a form of matter made solely of gluons, and utilized antimatter entanglement to resolve a 35-year-old particle physics measurement discrepancy.

4 sources. https://clstr.news/cluster/besiii-collaboration-identifies-glueball-matter-and-advances-particle-physics

### 2026-08-18: X(2370) particle provides strongest evidence for glueball

The BESIII Collaboration has identified the X(2370) particle as the strongest candidate yet for a glueball, potentially ending a 50-year search for a subatomic state made of gluons.

3 sources. https://clstr.news/cluster/x2370-particle-provides-strongest-evidence-for-glueball

### 2026-08-12: BESIII physicists find evidence of glueball particle X(2370)

Physicists at the BESIII experiment have found evidence that the X(2370) particle is a glueball, a theoretical composite particle made entirely of gluons.

4 sources. https://clstr.news/cluster/besiii-physicists-find-evidence-of-glueball-particle-x2370

### 2026-08-06: China's BESIII Experiment Confirms Existence of Glueball

Chinese scientists using BESIII have confirmed a glueball via the X(2370) particle, providing the first solid experimental proof of this long‑predicted form of matter.

3 sources. https://clstr.news/cluster/chinas-besiii-experiment-confirms-existence-of-glueball

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Cite as: BESIII confirms evidence of glueball particle X(2370). CLSTR, https://clstr.news/situations/besiii-glueball-particle-discovery