RS1, Custodial Isospin and Precision Tests
Kaustubh Agashe, Antonio Delgado, Michael J. May, Raman Sundrum
TL;DR
Addresses precision electroweak constraints in a non-supersymmetric RS1 framework with bulk gauge fields and fermions. Introduces a bulk custodial SU(2)_L x SU(2)_R x U(1)_{B-L} symmetry to keep the T parameter under control and uses AdS/CFT to interpret the setup as a dual conformal Higgs sector. Shows that tree-level and loop contributions to S and T can be kept consistent with data, requiring Kaluza-Klein resonances above about 3 TeV. Highlights distinctive collider signals arising from the custodial bulk structure and provides a 4D dual picture for the composite Higgs sector.
Abstract
We study precision electroweak constraints within a RS1 model with gauge fields and fermions in the bulk. The electroweak gauge symmetry is enhanced to SU(2)_L \times SU(2)_R \times U(1)_{B-L}, thereby providing a custodial isospin symmetry sufficient to suppress excessive contributions to the T parameter. We then construct complete models, complying with all electroweak constraints, for solving the hierarchy problem, without supersymmetry or large hierarchies in the fundamental couplings. Using the AdS/CFT correspondence our models can be interpreted as dual to a strongly coupled conformal Higgs sector with global custodial symmetry, gauge and fermionic matter being fundamental fields external to the CFT. This scenario has interesting collider signals, distinct from other RS models in the literature.