Five-dimensional models where the bulk is a slice of AdS have the virtue of solving the hierarchy problem. The electroweak scale is generated by a "warp" factor of the induced metric on the brane where the standard model fields live. However, it is not necessary to confine the standard model fields on the brane and we analyze the possibility of having the fields actually living in the slice of AdS. Specifically, we study the behaviour of fermions, gauge bosons and scalars in this geometry and their implications on electroweak physics. These scenarios may provide an explanation of the fermion mass hierarchy by warp factors. We also consider the case of supersymmetry in the bulk, and analyze the conditions on the mass spectrum. Finally, a model is proposed where the warp factor generates a small (TeV) supersymmetry-breaking scale, with the gauge interactions mediating the breaking to the scalar sector.
Bibliographical noteFunding Information:
We wish to thank Emilian Dudas, Oriol Pujolàs, and Daniel Waldram for helpful discussions. One of us (AP) acknowledges the ITP in Santa Barbara for hospitality during the initial stages of this work. The work of TG is supported by the FNRS, contract no. 21-55560.98, while that of AP is partially supported by the CICYT Research Project AEN99-0766.