New grand unified models with intersecting D6-branes, neutrino masses, and flipped image Original Research Article

We construct new supersymmetric image grand unified models based on image orientifolds with intersecting D6-branes. Unlike constructions based on image orientifolds, the orbifold images of the three-cycles wrapped by D6-branes correspond to new configurations and thus allow for models in which, in addition to the chiral sector in 10 and image representations of image, only, there can be new sectors with image and image vector-pairs. We construct an example of such a globally consistent, supersymmetric model with four-families, two Standard Model Higgs pair-candidates and the gauge symmetry image. In an image sector, there are image and image vector-pairs, while another image sector contains one vector-pair of 15-plets. The image vector-pairs can obtain a large mass dynamically by parallel D6-brane splitting in a particular two-torus. The 15-vector-pairs provide, after symmetry breaking to the Standard Model (via parallel D-brane splitting), triplet pair candidates which can in principle play a role in generating Majorana-type masses for left-handed neutrinos, though the necessary Yukawa couplings are absent in the specific construction. This model can also be interpreted as a flipped image grand unified model where the 10-vector-pairs can play the role of Higgs fields, though again there are phenomenological difficulties for the specific construction.