We develop a five-dimensional model for electroweak physics based on a noncompact warped extra dimension of finite length, known as the soft wall scenario, where all the dynamical degrees of freedom propagate in the five-dimensional bulk. We solve the equations of motion and find the allowed spectra, showing that the mass of the lightest fermionic mode behaves as a power law of the effective four-dimensional Yukawa coupling constant, with the exponent being the corresponding fermionic five-dimensional bulk mass. Precisely this nonuniversal behavior allows us to reproduce the hierarchy between the standard model fermion masses (from neutrinos to the top quark) with nonhierarchical fermionic bulk masses.

• Received 18 May 2009

DOI:https://doi.org/10.1103/PhysRevD.80.024030