Symmetry Remnants: Rationale for Having Two Higgs Doublets
arXiv:hep-ph/9301245 · doi:10.1103/PhysRevD.49.569
Abstract
There is a good reason why the standard electroweak SU(2) X U(1) gauge model may be supplemented by two Higgs scalar doublets. They may be remnants of the spontaneous breaking of an SU(2) X SU(2) X U(1) gauge symmetry at a much higher energy scale. In one case, the two-doublet Higgs potential has a custodial SU(2) symmetry and implies an observable scalar triplet. In another, a light neutral scalar becomes possible.
9 pages, UCRHEP-T103, TRI-PP-93-3, January 1993