Coset space dimensional reduction and classification of semi-realistic particle physics models
Starting from a Yang-Mills-Dirac theory defined in ten dimensions we classify the semi-realistic particle physics models resulting from their Forgacs-Manton dimensional reduction. The higher-dimensional gauge group is chosen to be E8. This choice as well as the dimensionality of the space-time is suggested by the heterotic string theory. Furthermore, we assume that the space-time on which the theory is defined can be written in the compactified form M4 × B, with M4 the ordinary Minkowski spacetime and B = S/R a 6 - dim homogeneous coset space. We constrain our investigation in those cases where the dimensional reduction leads in four dimensions to phenomenologically interesting and anomaly-free GUTs such as E6, SO(10) and SU(5). However the four-dimensional surviving scalars transform in the fundamental of the resulting gauge group are not suitable for the superstrong symmetry breaking of the Standard Model. The main objective of our work is the investigation to which extent the latter can be achieved by employing the Wilson flux breaking mechanism.