Fermion generations, masses and mixings in a 6D brane model

TL;DR

This paper explores a 6D brane model where fermion zero modes, distinguished by angular momentum, can explain fermion generations, masses, and mixings through a potential well trapping mechanism.

Contribution

It introduces a model where three normalizable zero modes correspond to fermion generations, linking angular momentum in extra dimensions to family number and mass hierarchy.

Findings

Three zero modes are localized near the brane.

Different profiles of zero modes enable realistic mass hierarchies.

Coupling to scalar fields can produce fermion mixing patterns.

Abstract

We study the motion of higher dimensional fermions in a non-singular 6D brane background with an increasing warp factor. This background acts as a potential well trapping fermions and fields of other spins near a 3+1 dimensional brane. By adjusting the shape of this potential well it is possible to obtain three normalizable zero mass modes giving a possible higher dimensional solution to the fermion generation puzzle. The three different zero mass modes correspond to the different angular momentum eigenvalues for rotations around the brane. This bulk angular momentum acts as the family or generation number. The three normalizable zero modes have different profiles with respect to the bulk, thus by coupling the higher dimensional fermion field to a higher dimensional scalar field it is possible to generate both a realistic mass hierarchy and realistic mixings between the different families.