Glueball

In particle physics, a glueball is a hypothetical composite particle. It consists solely of gluon particles, without valence quarks. Such a state is possible because gluons carry color charge and experience the strong interaction. Glueballs are extremely difficult to identify in particle accelerators, because they mix with ordinary meson states.

Theoretical calculations show that glueballs should exist at energy ranges accessible with current collider technology. However, due to the aforementioned difficulty, they have (as of 2011) so far not been observed and identified with certainty.

In lattice simulations

Lattice field theory provides a way to study the glueball spectrum theoretically and from first principles. Morningstar and Peardon have computed the masses of the lightest glueballs in QCD without dynamical quarks. The three lowest states are tabulated below. The presence of dynamical quarks would slightly alter these data, but also makes the computations more difficult.

J PC	mass
0++	1730(50)(80) MeV
2++	2400(25)(120) MeV
0−+	2590(40)(130) MeV

See also

• Exotic meson
• GlueX
• Gluon
• Yang–Mills theory

References and further reading

• Frank Close and Phillip R. Page, "Glueballs", Scientific American, vol. 279 no. 5 (November 1998) pp. 80–85
• Vincent Mathieu; Nikolai Kochelev; Vicente Vento (2009). "The Physics of Glueballs". International Journal of Modern Physics E 18: 1–49. Bibcode 2009IJMPE..18....1M. doi:10.1142/S0218301309012124. 
• Glueball on arxiv.org