Neutrino democracy and other phenomenology from 5D <f>SO(10)</f>

We present a five-dimensional supersymmetric <f>SO(10)</f> model compactified on an orbifold <f>S(1)/Z2×Z2′</f>. The gauge symmetry <f>G422≡SU(4)c×SU(2)L×SU(2)R</f>, realized on one of the fixed points (branes), is spontaneously broken to the MSSM via the Higgs mechanism. Employing a flavor <f>U(1)</f> symmetry and suitably extending the ‘matter’ sector enables us to understand large mixings in the neutrino sector via a democratic approach, vs. the small CKM mixings. A residual <f>R</f>-symmetry on <f>G422</f> brane helps eliminate the troublesome dimension five nucleon decay, while the <f>U(1)</f> symmetry plays an essential role in suppressing dimension six decay. For rare leptonic decays we expect <f>BR(μ→eγ)∼BR(τ→μγ)∼BR(τ→eγ)</f>. [Copyright &y& Elsevier]