A calculation that took 2 years on a powerful special-purpose computer has provided evidence that a hypothesized subnuclear particle called a
glueball actually exists.
Schechter, "Pseudoscalar
glueball, the axial-vector anomaly, and the mixing problem for pseudoscalar mesons," Physical Review D: Particles, Fields, Gravitation and Cosmology, vol.
da Rocha, "Dark SU(N)
Glueball Stars on Fluid Branes," arXiv:1701.00761 hep-ph.
This observation agrees, for example, with [47], where gluon and chiral condensates were studied at finite temperature with an effective Lagrangian of pseudoscalar mesons coupled to a scalar
glueball. The gluon condensates were found to be very stable up to temperatures of 200 MeV, where the chiral sector of the theory reaches its limit of validity [47].
That is why Messchendorp wants protons to collide with antiprotons to create
glueballs, exotic states that contain gluons.
QCD experts have predicted the existence of
glueballs [22].
Topics of the two summary talks include heavy quark hadrons and theory, and
glueballs, hybrids, baryons and pentaquarks.
By 1995, two further years of calculations had established both the mass and the decay rate of an elusive subfamily of hadrons, called
glueballs, which had gone unrecognized in preceding laboratory experiments.