2003/10/20 by Kokorelis, Christos
#FOS: Physical sciences #High Energy Physics - Theory (hep-th)
paper · doi:10.48550/arxiv.hep-th/0310194
We provide a general overview of the current state of the art in three generation model building proposals - using intersecting D-brane toroidal compactifications of IIA string theories - which have, only, the SM at low energy. In this context, we focus on these model building directions, where natural non-supersymmetric constructions based on SU(4)C × SU(2)L × SU(2)R, SU(5) and flipped SU(5) GUT groups, have at low energy only the Standard Model. In the flipped SU(5) GUTS, the special build up structure of the models accommodates naturally a see-saw mechanism and a new solution to the doublet-triplet splitting problem.