The Hierarchy Problem and the Self-Localized Higgs

Abstract

We examine brane-world scenarios in which all the observed Standard Model particles reside on a brane but the Higgs is an elementary extra-dimensional scalar in the bulk. We show that, for codimension 2 branes, often-neglected interactions between the bulk Higgs and the branes cause two novel effects. First, they cause <H> to depend only logarithmically on the UV-sensitive coefficient, m_B^2, of the mass term, m_B^2 H^*H, of the bulk potential, thus providing a new mechanism for tackling the hierarchy problem. Second, the Higgs brane couplings cause the lowest mass KK mode to localize near the brane without any need for geometrical effects like warping. We explore some preliminary implications such models have for the Higgs signature at the LHC, both in the case where the extra dimensions arise at the TeV scale, and in ADD models having Large Extra Dimensions. Novel Higgs features include couplings to fermions which can be different from Standard Model values, m_f/v, despite the fermions acquiring their mass completely from the Higgs expectation value.