1207.5194 (M. Aa. Solberg)

Exact subsymmetries of the custodial SO(4) symmetry    [PDF]

M. Aa. Solberg

We show that there is no symmetry which, imposed on the general charge conjugation (C) invariant multi-Higgs-doublet model (NHDM), excludes exactly the O(4) violating terms from the potential. This is in part done by determining the exact subsymmetries of the custodial SO(4) symmetry of the standard model (SM) scalar Lagrangian. Furthermore, the Higgs family symmetries of the quadratic part of the general C invariant NHDM potential, will also be symmetries of the O(4) violating terms of the potential. Finally, we also show there is no possibility of extending the custodial SO(4) symmetry by elements of O(4)-SO(4). Hence the custodial SO(4) symmetry is the largest symmetry group of the scalar sector of the SM in the limit g' -> 0.

View original: http://arxiv.org/abs/1207.5194