Neutrinos, their Partners and Unification

Efforts to unify group-theoretically the standard-model gauge interactions with the generation structure of fermions and their mirror partners should be accompanied with the unification of the corresponding gauge couplings. In this paper the possibility of such a unification is studied and conclusions on possible symmetry-breaking channels and scales, as well as on the fermion content of the theory, are drawn. The breaking of some of the symmetries allows various Majorana masses for neutrinos and their mirror partners, so these are studied next. Implications to neutrino mixings and mass hierarchies in connection with recent experimental results, as well as to electroweak precision tests, are then discussed.Comment: 35 Latex pages, improved versio

Strongly-interacting fermions from a higher-dimensional unified gauge theory

The method of coset-space dimensional reduction is employed in order to proceed from a gauged E_8 * E_8' unified theory defined in 10 dimensions to 4 dimensions. The resulting theory comprises the Standard Model along with a strongly-interacting fermion sector which breaks the electroweak symmetry dynamically at the right scale.Comment: 12 LaTeX pages, version to be published in Physics Letters

Mass generation and the dynamical role of the Katoptron Group

Heavy mirror fermions along with a new strong gauge interaction capable of breaking the electroweak gauge symmetry dynamically were recently introduced under the name of katoptrons. Their main function is to provide a viable alternative to the Standard-Model Higgs sector. In such a framework, ordinary fermions acquire masses after the breaking of the strong katoptron group which allows mixing with their katoptron partners. The purpose of this paper is to study the elementary-scalars-free mechanism responsible for this breaking and its implications for the fermion mass hierarchies.Comment: 15 LaTeX pages, some comments added, version published in Modern Physics Letters