LHC Signals for Warped Electroweak Charged Gauge Bosons

TL;DR

This paper investigates the potential for detecting Kaluza-Klein excitations of charged electroweak gauge bosons at the LHC within a warped extra dimension model, highlighting unique decay channels and experimental sensitivities.

Contribution

It introduces the LHC search strategies for charged KK gauge bosons in warped extra dimensions, emphasizing decay channels with no QCD background and improved reconstruction techniques.

Findings

Sensitivity to 2-3 TeV KK masses with 100-300 fb^{-1} luminosity.

Decay channels to WZ and top-bottom final states are promising for discovery.

Enhanced decay rates to longitudinal W, Z, and Higgs bosons.

Abstract

We study signals at the Large Hadron Collider (LHC) for the Kaluza-Klein (KK) excitations of electroweak charged gauge bosons in the framework of the Standard Model (SM) fields propagating in the bulk of a warped extra dimension. Such a scenario can solve both the Planck-weak and flavor hierarchy problems of the SM. There are two such charged states in this scenario with couplings to light quarks and leptons being suppressed relative to those in the SM, whereas the couplings to top/bottom quarks are enhanced, similar to the case of electroweak neutral gauge bosons previously studied. However, unlike the case of electroweak neutral gauge bosons, there is no irreducible QCD background (including pollution from possibly degenerate KK gluons) for decays to top + bottom final state so that this channel is useful for the discovery of the charged states. Moreover, decays of electroweak charged gauge bosons to longitudinal W, Z and Higgs are enhanced just as for the neutral bosons. However, unlike for the neutral gauge bosons, the purely leptonic (and hence clean) decay mode of the WZ are fully reconstructible so that the ratio of the signal to the SM (electroweak) background can potentially be enhanced by restricting to the resonance region more efficiently. We show that such final states can give sensitivity to 2 (3) TeV masses with an integrated luminosity of 100 (300) inverse fb. We emphasize that improvements in discriminating a QCD-jet from a highly boosted hadronically decaying W, and a highly boosted top-jet from a bottom-jet will enhance the reach for these KK particles, and that the signals we study for the warped extra dimensional model might actually be applicable also to a wider class of non-supersymmetric models of electroweak symmetry breaking.