{
  "id": 6286191,
  "title": "Missing decay at BESIII points to long-sought glueball",
  "url": "https://urgent.news/2026/09/08/missing-decay-at-besiii-points-to-long-sought-glueball",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-08T13:41:50.000Z",
  "source": {
    "name": "Physics World",
    "slug": "physics-world",
    "url": "https://physicsworld.com/a/missing-decay-at-besiii-points-to-long-sought-glueball/"
  },
  "original_language": "en",
  "account": "Physicists at China’s BESIII experiment have discovered compelling evidence for the existence of glueballs – subatomic particles comprised solely of gluons. The particle in question, X(2370), was first observed at BESIII 15 years ago. Gluons are responsible for the strong nuclear force that binds quarks together in protons and neutrons, and they also repel each other. Glueballs should theoretically form when gluons clump together, and their discovery would represent a new form of matter. The BESIII experiment, located at BEPCII accelerator, collides electrons with positrons to generate numerous J/ψ particles. Occasionally, a J/ψ decays, releasing a burst of light and transferring the remaining energy to gluons, which can then combine to form a glueball. The lightest possible glueball, X(2370), was discovered in 2011. Determining its spin-parity quantum numbers, a unique identifier, proved difficult due to substantial background processes. In 2024, with a clean decay chain and all 10 billion J/ψ particles, the team confirmed the particle's properties, matching predictions for the lightest glueball. Further, the team searched for a specific decay channel unique to X(2370) and discovered that its absence supports its classification as the lightest glueball. This discovery confirms a key prediction of Quantum Chromodynamics (QCD), the theory of the strong force, which posits that gluons should self-couple. The findings also provide insights into mass generation. While some may argue for an independent confirmation, the discovery marks a significant experimental triumph.",
  "summary": "Heavy particle could be dominated by gluons The post Missing decay at BESIII points to long-sought glueball appeared first on Physics World .",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}