2006/07/31 by Marcela Carena, Eduardo Ponton, Eduardo Pontón +3 · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Electroweak interaction #Geometry #Higgs boson #Homogeneous space #Observable #Parameter space #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #hep-ph
paper · pdf · doi:10.1016/j.nuclphysb.2006.10.012
published as Nucl.Phys.B759:202-227,2006 · 35 pages, 7 figures
arxiv created 2006/08/03 · openalex publication_date 2006/10/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We consider Randall-Sundrum scenarios based on SU(2)L x SU(2)R and a discrete parity exchanging L with R. The custodial and parity symmetries can be used to make the tree level contribution to the T parameter and the anomalous couplings of the bottom quark to the Z very small. We show that the resulting quantum numbers typically induce a negative T parameter at one loop that, together with the positive value of the S parameter, restrict considerably these models. There are nevertheless regions of parameter space that successfully reproduce the fit to electroweak precision observables with light Kaluza-Klein excitations accessible at colliders. We consider models of gauge-Higgs unification that implement the custodial and parity symmetries and find that the EW data singles out a very well defined region in parameter space. In this region one typically finds light gauge boson Kaluza-Klein excitations as well as light SU(2)L singlet, and sometimes also doublet, fermionic states, that mix with the top quark, and may yield interesting signatures at future colliders.