China's BESIII Experiment Confirms Existence of Glueball

Researchers from the Institute of High Energy Physics, under the Chinese Academy of Sciences, announced that the Beijing Spectrometer III (BESIII) experiment has provided the first definitive experimental evidence of a glueball, a new form of matter composed solely of gluons. The team studied decays of more than 10 billion J/ψ particles collected at the Beijing Electron‑Positron Collider II, identifying the particle X(2370) and measuring its quantum numbers, mass and flavor‑singlet nature in line with theoretical predictions for a pseudoscalar glueball.

The discovery, achieved after 15 years of work, validates a long‑standing prediction of quantum chromodynamics and offers a crucial test of the Standard Model, marking the most compelling evidence for glueballs in half a century of searches.