leptoquark

A leptoquark is a hypothetical elementary particle that carries both lepton and baryon number. In the Standard Model of particle physics, leptons and quarks are considered fundamental and distinct. Leptons, such as electrons and neutrinos, do not interact via the strong nuclear force, while quarks do. Leptoquarks, if they exist, would mediate interactions between leptons and quarks.

The existence of leptoquarks is predicted by various extensions to the Standard Model, including Grand Unified Theories (GUTs). These theories propose that at very high energies, the fundamental forces of nature, including the electromagnetic, weak, and strong forces, unify. Leptoquarks would be the carriers of these unified interactions at lower energies.

Leptoquarks would appear as either bosons or fermions, depending on the specific theoretical model. They are also expected to have fractional electric charges and could decay into both lepton-quark or antiquark-antilepton pairs. The search for leptoquarks is an active area of experimental particle physics, with experiments at particle colliders like the Large Hadron Collider (LHC) looking for evidence of their production and decay. No definitive experimental evidence for leptoquarks has been found to date, but ongoing searches continue to constrain their possible properties and masses.