Reducing Constraints in a Higher Dimensional Extension of the Randall and Sundrum Model

TL;DR

This paper explores higher-dimensional warped spaces extending the Randall-Sundrum model, analyzing how additional warped dimensions influence the KK spectrum and electroweak bounds, potentially lowering the KK mass scale to around 2 TeV.

Contribution

It introduces a $4+1+ ext{delta}$ dimensional extension of the RS model with anisotropic warping, analyzing the impact on gauge KK spectra and electroweak bounds.

Findings

KK mass bounds are approximately 2 TeV for both gauge symmetries.

Additional warped dimensions can reduce constraints on the KK scale.

First gauge boson excitation masses are about 4-6 TeV.

Abstract

In order to investigate the phenomenological implications of warped spaces in more than five dimensions, we consider a $4+1+\delta$ dimensional extension to the Randall and Sundrum model in which the space is warped with respect to a single direction by the presence of an anisotropic bulk cosmological constant. The Einstein equations are solved, giving rise to a range of possible spaces in which the $\delta$ additional spaces are warped. Here we consider models in which the gauge fields are free to propagate into such spaces. After carrying out the Kaluza Klein (KK) decomposition of such fields it is found that the KK mass spectrum changes significantly depending on how the $\delta$ additional dimensions are warped. We proceed to compute the lower bound on the KK mass scale from electroweak observables for models with a bulk $SU(2)\times U(1)$ gauge symmetry and models with a bulk $SU(2)_R\times SU(2)_L\times U(1)$ gauge symmetry. It is found that in both cases the most favourable bounds are approximately $M_{KK}\gtrsim 2$ TeV, corresponding to a mass of the first gauge boson excitation of about 4-6 TeV. Hence additional warped dimensions offer a new way of reducing the constraints on the KK scale.