Editing Seesaw mechanism (section)

{{Short description|Model in particle physics}}
In the [[Grand Unified Theory|theory of grand unification]] of [[particle physics]], and, in particular, in theories of [[neutrino]] masses and [[neutrino oscillation]], the '''seesaw mechanism''' is a generic model used to understand the relative sizes of observed neutrino masses, of the order of [[electronvolt|eV]],  compared to those of [[quark]]s and charged [[lepton]]s, which are millions of times heavier. The name of the seesaw mechanism was given by [[Tsutomu Yanagida]] in a Tokyo conference in 1981.

There are several types of models, each extending the [[Standard Model]].  The simplest version, "Type 1", extends the Standard Model by assuming two or more additional right-handed neutrino fields
inert under the electroweak interaction,{{efn|
It is possible to generate two low-mass neutrinos with only one right-handed neutrino, but the resulting mass spectra are generally not viable.
}}
and the existence of a very large mass scale. This allows the mass scale to be identifiable with the postulated scale of grand unification.