arXiv:hep-ph/9710492·v1·High Energy Physics — Phenomenology
Group-Theoretic Evidence for SO(10) Grand Unification
J. Lykken🇺🇸 · T. Montroy🇺🇸 · S. Willenbrock🇺🇸
Abstract
The hypercharges of the fermions are not uniquely determined in SO(10) grand unification, but rather depend upon which linear combination of the two U(1) subgroups of SO(10) > SU(3) X SU(2) X U(1) X U(1) remains unbroken. We show that, in general, a given hypercharge assignment can be obtained only with very high-dimensional Higgs representations. The observation that the standard model is obtained with low-dimensional Higgs representations can therefore be regarded as further evidence for SO(10) grand unification. This evidence is independent of the fact that SO(10) > SU(5).
Comments: 6 pages, LateX