Gaugino

Part of speech: noun

Definitions

1. A hypothetical heavy particle that is the supersymmetric partner of a gauge boson, predicted by theories extending the Standard Model of physics
2. A theoretical fermion paired with a gauge boson under supersymmetry, whose existence would balance the particle spectrum in advanced physics models
3. In particle physics, a postulated spin-one-half partner of a force-carrying boson, proposed within supersymmetric theories of fundamental interactions

Etymology: Gaugino is a physics term for the hypothetical supersymmetric partner of a gauge boson, and its name is a deliberate piece of wordplay. It combines "gauge," the term for the force-carrying bosons described by gauge theory, with the suffix "-ino," which physicists had already attached to particle names such as "neutrino," where it marks a small, neutral particle. Putting the two together produces a name for a gauge partner that sounds like a little neutral particle, which fits the naming pattern used across supersymmetry. The "-ino" convention follows the same logic. Supersymmetry pairs each known particle with a superpartner, and these are named by adding a suffix to the original name: "squark" for quark partners, "slepton" for lepton partners, and "-ino" for the fermionic partners of bosons. Gaugino therefore names the spin-½ partner of a gauge boson, such as the gluon, the W and Z bosons, or the photon. None of these particles has been observed, so the term describes a theoretical construction rather than a detected object.