Speaker
Description
We provide a systematic construction of three-family N=1 supersymmetric Pati-Salam models from Type IIA orientifolds on T^6/(Z_2 × Z_2) with intersecting D6-branes. All the gauge symmetries SU(4)C × SU(2)_L × SU(2)_R arise from the stacks of D6-branes with U(n) gauge symmetries, while the hidden sector is specified by USp(n) D6-branes. The Pati-Salam gauge symmetry can be broken down to the SU(3)_C × SU(2)_L × U(1){B-L} × U(1){I{3R}} via D6-brane splittings, and further down to the Standard Model (SM) via the D- and F-flatness preserving Higgs mechanism from massless open string states in a N=2 subsector. We show that there are only 33 independent models with different gauge coupling relations at string scale after modding out equivalent relations. We study the gauge coupling unification, SM fermion masses and mixing, as well as supersymmetry breaking soft terms. In addition, to forbid the open string moduli, we consider rigid D6-branes. We construct, for the first time, the three-family supersymmetric Pati-Salam models from rigid intersecting D6-branes on a factorizable orientifold with discrete torsion, and discuss their phenomenological implications as well.
