Flipped SU(5) X U(1)_X Models from F-Theory

Understand

We systematically construct flipped SU(5) X U(1)_X models without and with bulk vector-like particles from F-theory.

• To realize the decoupling scenario, we introduce sets of vector-like particles in complete SU(5) X U(1) multiplets at the TeV scale, or at the intermediate scale, or at the TeV scale and high scale.
• To avoid the Landau pole problem for the gauge couplings, we can only introduce five sets of vector-like particles around the TeV scale.
• These vector-like particles can couple to the Standard Model singlet fields, and obtain suitable masses by Higgs mechanism.