We study the electroweak and U(1)′ symmetry breaking patterns in models with the particle content of supersymmetric E6, including standard model singlets S and exotic quarks D, D̄. Motivated by free fermionic string models, we do not require E6-type relations between Yukawa couplings. In particular, we assume that baryon and lepton numbers are conserved, so that the exotic quarks can be light. Gauge invariance allows Yukawa interactions between S and Higgs doublets, and between S and the exotic quarks, allowing radiative U(1)′ symmetry breaking and the generation of an effective μ parameter at the electroweak scale. For both the E6 ψ and η models, universal soft supersymmetry breaking parameters and Yukawa universality at the high (string) scale do not yield acceptable low energy phenomenology. Relaxing universality, we find solutions with phenomenologically acceptable values of MZ′ and the Z-Z′ mixing angle. In addition, by varying the U(1)′ charge assignments due to the mixing of U(1)χ and U(1)ψ of E6, it is possible to have acceptable low energy phenomenology with universal boundary conditions.
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Dec 1 1998|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)