BESIII experiment finds evidence for glueball particles

Physicists working with the BESIII experiment in Beijing have presented strong evidence for the existence of glueballs, which are hypothetical subatomic particles composed entirely of gluons rather than quarks or leptons.

The research focuses on the X(2370) particle, first observed in 2011. While its existence was previously known, recent analysis of approximately 10 billion charmonium decays allowed scientists to determine its quantum numbers. These numbers align with theoretical predictions for the lightest pseudoscalar glueball.

A key finding in the latest study involves the absence of a specific decay. If X(2370) contained quarks, it should frequently decay into K*(892) mesons and antikaons. However, researchers found no evidence of this decay, which supports the theory that the particle is a glueball, as such a decay would be forbidden for a purely gluon-based state.