Grand Unified Theory

quantum field theory in which the three gauge groups of the standard model combine into subgroups of a larger gauge group

hypothetical decay process of a nucleon (proton or neutron) into non-nucleons (anything else)

charged massive gauge bosons in the SU(5) Georgi–Glashow grand unified model mediating proton decay, filling out the adjoint representation of SU(5) together with the gluon, the photon and the W and Z bosons

Leptoquarks are hypothetical particles that would interact with quarks and leptons. Leptoquarks are color-triplet bosons that carry both lepton and baryon numbers. Their other quantum numbers, like spin, (fractional) electric charge and weak isospin vary among models. Leptoquarks are encountered in various extensions of the Standard Model, such as technicolor theories, theories of quark–lepton unification (e.g., Pati–Salam model), or Grand Unified Theories based on SU(5), SO(10), E6, etc. Leptoquarks are currently searched for in experiments ATLAS and CMS at the Large Hadron Collider in CERN.

energy scale (10¹⁶ GeV) at which the electroweak interaction and the strong interaction may unify

grand unified model based on the gauge group SU(5), ruled out by limits on proton decay

grand unified theory proposed in 1974 by Abdus Salam and Jogesh Pati based on the gauge group SU(4)×SU(2)×SU(2) in which the four colour corresponds to leptons