The symmetry breaking of five-dimensional SU(6) GUT is realized by Scherk-Schwarz mechanisms through trivial and pseudo nontrivial orbifold S1/Z2 breakings to produce dimensional deconstruction 5D SU(6) rightarrow4D SU(6). The latter also induces nea
r-brane weakly-coupled SU(6) Baby Higgs to further break the symmetry into SU(3)C otimes SU(3)H otimes U(1)C. The model successfully provides a scenario of the origin of (Little) Higgs from GUT scale, produces the (intermediate and light) Higgs boson with the most preferred range and establishes coupling unification and compactification scale correctly.
Proton decay within 5-dimensional SU(6) GUT with orbifold S^1/Z_2 breaking is investigated using Scherk-Schwarz mechanism. It is shown that in the model neither leptoquark like heavy gauge bosons nor violation of baryon number conservation are allowe
d due to the orbifold breaking parity splitting. These results prevent too short proton lifetime within the model.
The symmetry breaking of 5-dimensional SU(6) GUT into 4-dimensional SU(3) x SU(3) x U(1) with orbifold S1/Z2 through Scherk-Schwarz mechanism is investigated. It is shown that the origin of Little Higgs can be generated to further break SU(3) x SU(3)
x U(1) down to the electroweak scale through Higgs mechanism.
