Model with Gauge Coupling Unification on $S^1\mathrm{/}(Z_2\times Z_2^{\mathrm{\prime }})$ Orbifold

We suggest a simple grand unified theory where the fifth dimensional coordinate is compactified on an $S^1\mathrm{/}(Z_2\times Z_2^{\mathrm{\prime }})$ orbifold. This model contains additional $\mathbf{10}+\overline{\mathbf{10}}$, ($\mathbf{15}+\overline{\mathbf{15}}$) and two $\mathbf{24}$ Higgs multiplets in the non-supersymmetric SU(5) grand unified theory. Although this model is non-supersymmetric theory, the gauge coupling unification is realized due to the mass splittings of Higgs multiplets by $S^1\mathrm{/}(Z_2\times Z_2^{\mathrm{\prime }})$ orbifolding. The constraints from the $b \to s \gamma$,$\mu \to e \gamma$, and electron and muon anomalous magnetic moments are also discussed.