Gauge boson certain atoms. The Standard Model of particle physics recognizes four kinds of gauge bosons: photons, which carry the electromagnetic interaction; W and Z bosons, which carry the weak interaction; and gluons, which carry the strong interaction. Isolated gluons do not occur because they are color-charged and subject to color confinement. In a quantized gauge theory, gauge bosons are quanta of the gauge fields. Consequently, there are as many gauge bosons as there are generators of the gauge field. In quantum electrodynamics, the gauge group is "U"(1); in this simple case, there is only one gauge boson. In quantum chromodynamics, the
X and Y bosons X and Y bosons In particle physics, the X and Y bosons (sometimes collectively called "X bosons") are hypothetical elementary particles analogous to the W and Z bosons, but corresponding to a new type of force predicted by the Georgi–Glashow model, a grand unified theory. The X and Y bosons couple quarks to leptons, allowing violation of the conservation of baryon number, and thus permitting proton decay. An X boson would have the following decay modes: where the two decay products in each process have opposite chirality, is an up quark, is a down antiquark and is a positron. A