Electroweak constraints on warped models with custodial symmetry

By M. Carena, E. Pontón, J. Santiago, C. Wagner. 2007

197 citations recorded by the source corpus.

It has been recently argued that realistic models with warped extra dimensions can have Kaluza-Klein particles accessible at the CERN Large Hadron Collider if a custodial symmetry, $SU(2{)}_{V}\ifmmode\times\else\texttimes\fi{}{P}_{LR}$, is used to protect the $T$ parameter and the coupling of the left-handed bottom quark to the $Z$ gauge boson. In this article we emphasize that such a symmetry implies that the loop corrections to both the $T$ parameter and the $Z{b}_{L}{\overline{b}}_{L}$ coupling are calculable. In general, these corrections are correlated, can be sizable, and should be considered to determine the allowed parameter space region in models with warped extra dimensions and custodial symmetry, including Randall-Sundrum models with a fundamental Higgs, models of gauge-Higgs unification, and Higgsless models. As an example, we derive the constraints that arise on a representative model of gauge-Higgs unification from a global fit to the precision electroweak observables. A scan over the parameter space typically leads to a lower bound on the Kaluza-Klein excitations of the gauge bosons of about 2\char21{}3 TeV, depending on the configuration. In the fermionic sector one can have Kaluza-Klein excitations with masses of a few hundred GeV. We present the constraints on these light fermions from recent Tevatron searches, and explore interesting discovery channels at the LHC.

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Citations in the corpus

ΔF = 2 observables and fine-tuning in a warped extra dimension with custodial protection (2008, methodology): “One of our strategies will be to find regions of parameter space consistent with EW precision observables [10, 11, 16] for which QLR is sufficiently suppressed even if the 5D Yukawa couplings are mostly anarchic.”
Rare K and B Decays in a warped extra dimension with custodial protection (2008, methodology): “In our numerical analysis we will use f = 1 TeV.”
Light top partners and precision physics (2013, background): “oblique EW parameters due to fermion loops in this class of theories have been considered in the literature [65, 73, 74], however no divergent or enhanced contribution was noticed.”
The flavor of the composite pseudo-goldstone Higgs (2008, methodology): “Apart from yielding the correct electroweak breaking vacuum, phenomenologically acceptable GHU models must pass stringent electroweak precision tests [35, 27].”
Electroweak and Flavour Structure of a Warped Extra Dimension with Custodial Protection (2009, methodology): “In particular the representations given below can easily be embedded into complete SO(5) multiplets used in [14, 23, 66] in the context of models with gaugeHiggs unification.”
Higgs boson from an extended symmetry (2007, methodology): “was supported by the EU under RTN contract MRTN-CT-2004(14)A relevant study has been recently preformed in [19] for warped holographic extensions, although the modification of the Higgs contributions to T and S with respect to the SM, eq.”
Constraints on new phenomena via Higgs boson couplings and invisible decays with the ATLAS detector (2015, methodology): “Similarly, the MCHM5 model [48, 49] is an SO(5)/SO(4) model where the SM fermions are embedded in fundamental representations of SO(5).”