Discovery of the gluon

The gluon, the particle responsible for strong interactions, was discovered at the accelerator PETRA of DESY, Germany, in 1979. It is the second gauge boson to have been discovered experimentally, the first one being the photon. Furthermore, it is the first Yang‐Mills non‐Abelian gauge boson, meaning that, unlike the photon, the gluon has self‐interactions. Its discovery was followed, four years later in 1983, by that of the second and the third non‐Abelian gauge bosons, the Z and the W, at CERN, Switzerland. This article gives the history of the discovery of the gluon via the observation of three‐jet events from the process e⁺e⁻→qq̄g.