IV.D201 — Glueball

A glueball is a bound state of the strong vacuum field Gamma_s^* with no quark content: a color-neutral excitation of the su(3) connection field above the vacuum minimum, carrying positive mass at or above the Yang-Mills mass gap m_gap, predicted by lattice QCD at ~1.5-1.7 GeV for J^PC = 0^++.