Composite quarks and leptons in higher space-time dimensions

Abstract

A new approach towards the composite structure of quarks and leptons in the context of the higher dimensional unified theories is proposed. Owing to the certain strong dynamics, much like an ordinary QCD, every possible vectorlike set of composites appears in higher dimensional bulk space-time, however, through a proper Sherk-Schwarz compactification only chiral multiplets of composite quarks and leptons survive as the massless states in four dimensions. In this scenario restrictions related with the 't Hooft's anomaly matching condition are turned out to be avoided and, as a result, the composite models look rather simple and economic. We demonstrate our approach by an explicit construction of model of preons and their composites unified in the supersymmetric SU(5) GUT in five space-time dimensions. The model predicts exactly three families of the composite quarks and leptons being the triplets of the chiral horizontal symmetry SU(3) h which automatically appears in the composite spectrum when going to ordinary four dimensions.

Preon Model and Family Replicated E6 Unification

“…They are actually necessary for the entire set of composite quark-leptons and bosons (see [30]). The hyper-magnetic interaction is assumed to be responsible for the formation of E 6 fermions and bosons at the compositeness scale Λ s .…”

Sfermion Mass Relations in Orbifold Family Unification

“…6)] derived from [6,3] - [9,4] are listed in Table V. We have classified the mass relations into three types, but the forms of the mass relations are not unique.…”

Are preons dyons? Naturalness of three generations

“…which are actually necessary for the entire set of composite quark-leptons and bosons [22]. The hyper-magnetic interaction is assumed to be responsible for the formation of E 6 fermions and bosons at the compositeness scale Λ s .…”

“…A preonic model of composite quarks and leptons in higher space-time dimensions was constructed in Ref. [22]. Their results are utilized in our present model of preons.…”

“…Taking into account the role of compactification [39] we start, as in Ref. [22], with N = 1 supersymmetric gauge theory in 5D dimensions with a local symmetry gauge group G, which is equal to the flipped E 6 in our case. The matter fields transform according to one of the irreducible representations of G: for example, we have the 27-plet of E 6 given by Eqs.…”