Randall-Sundrum Models and Precision Observables

TL;DR

This paper reviews the phenomenological implications of Randall-Sundrum models with bulk fermions and a brane-localized Higgs, focusing on precision electroweak observables and resulting bounds on Kaluza-Klein modes.

Contribution

It provides a comprehensive analysis of how precision measurements constrain RS models, including effects of Higgs mass variations and alternative model approaches.

Findings

Severe bounds on KK mode masses from electroweak observables.

Bounds are highly sensitive to the Higgs boson mass.

Heavy Higgs boson can significantly relax constraints.

Abstract

I present a review of phenomenological implications of the Randall-Sundrum (RS) model with bulk fermions and brane-localized Higgs boson. Modifications to the W-boson mass, corrections to the Peskin-Takeuchi parameters and to the Z -> bb couplings will be discussed. From these observables severe bounds on the mass scale of Kaluza-Klein (KK) modes arise. Constraints from all three observables are very sensitive to the exact value of the Higgs boson mass and the bounds can be significantly lowered by allowing for a heavy Higgs boson (m_h ~ 1 TeV). Consequences thereof, as well as other approaches like "little RS" models and models with custodial symmetry will also be briefly discussed.