Hierarchy problem and new warped extra dimension

Abstract

In this paper, we propose a new mechanism with a warped extra dimension to solve the hierarchy problem, which is parallel to the Randall-Sundrum (RS) brane scenario. Different from the RS scenario, the fundamental scale is TeV scale, and the four-dimensional Planck scale is generated from the exponential warped extra dimension at size of a few TeV-1. The experimental consequences of this scenario are very different from that of the RS scenario. In the explicit realization in the nonlocal gravity theory, there is a tower of spin-2 excitations with mass gap 10-4 eV, and they are coupled with the gravitational scale to the standard model particles. We further discuss the possible generalizations in other modified gravity theories. The experimental consequences are similar to a (4+N)-dimensional large extra dimension, but N can be a noninteger, which satisfies the experimental constraints more easily than the integer large extra-dimension model.