Glueball

About Glueball

• A glueball is a bound state formed when gluons attract and bind with each other.
• Formation Process:
  • Quarks: Quarks are the particles that are tightly bound inside protons and neutrons by the strong interaction.
  • The strong force holds quarks together inside protons and neutrons.
    • This force is mediated by particles called gluons, just as the electromagnetic force is mediated by photons.
  • Gluon attraction: Unlike photons, gluons can attract each other because they carry a kind of charge.
    • This allows gluons to bind with one another.
  • Glueball formation: When gluons bind together, they can form a composite particle called a glueball, which is an important prediction of quantum chromodynamics (QCD).
• Key Features:
  • Evidence: Scientists first identified a candidate glueball in 2011.
    • In 2024, using data from 10 billion J/ψ particles, they found that its properties matched the predictions for a pseudoscalar glueball.
  • Further evidence: Newly discovered decay modes established its flavor-singlet nature, the most important characteristic of a glueball.
  • Importance: The findings provide the clearest experimental result from nearly 50 years of searches and strongly test QCD by supporting its prediction that gluons can form a new type of matter.

Quantum Chromodynamics (QCD)

• Quantum Chromodynamics (QCD) is the fundamental physics theory that describes the strong interaction, which is the most powerful of the four fundamental forces in nature (gravity, weak force, electromagnetism and strong force).
• Role: It explains how quarks, the building blocks of matter, are bound together by gluons, which are force-carrying particles.
• Development: QCD was formulated in 1973 by physicists including Murray Gell-Mann.