Standard-like model building on type II orientifolds

Abstract

We construct new standard-like models on type II orientifolds. In type IIA theory on T 6 / ( Z 2 × Z 2 ) orientifold with intersecting D6-branes, we first construct a three-family trinification model where the U ( 3 ) C × U ( 3 ) L × U ( 3 ) R gauge symmetry can be broken down to the SU ( 3 ) C × SU ( 2 ) L × U ( 1 ) Y L × U ( 1 ) I 3 R × U ( 1 ) Y R gauge symmetry by the Green–Schwarz mechanism and D6-brane splittings, and further down to the SM gauge symmetry at the TeV scale by Higgs mechanism. We also construct a Pati–Salam model where we may explain three-family SM fermion masses and mixings. Furthermore, we construct for the first time a Pati–Salam like model with U ( 4 ) C × U ( 2 ) L × U ( 1 ) ′ × U ( 1 ) ″ gauge symmetry where the U ( 1 ) I 3 R comes from a linear combination of U ( 1 ) gauge symmetries. In type IIB theory on T 6 / ( Z 2 × Z 2 ) orientifold with flux compactifications, we construct a new flux model with U ( 4 ) C × U ( 2 ) L × U ( 2 ) R gauge symmetry where the magnetized D9-branes with large negative D3-brane charges are introduced in the hidden sector. However, we cannot construct the trinification model with supergravity fluxes because the three SU ( 3 ) groups already contribute very large RR charges. The phenomenological consequences of these models are briefly discussed as well.