Light pseudo-Goldstone Higgs boson from SO(10) GUT with realistic phenomenology

Within the supersymmetric SO(10) grand unified theory (GUT), a new mechanism giving the light Higgs doublet as a pseudo-Goldstone mode is suggested. Realizing this mechanism, we present an explicit model with fully realistic phenomenology. In particular, desirable symmetry breaking and natural all-order hierarchy are achieved. The constructed model allows one to have a realistic fermion pattern, nucleon stability, and successful gauge coupling unification. The suggested mechanism opens prospects in the field for a novel SO(10) GUT model building and for further investigations.