The framework of a warped extra dimension with the standard model (SM) fields propagating in it is a very well-motivated extension of the SM since it can address both the Planck-weak and flavor hierarchy problems of the SM. Within this framework, solution to the little hierarchy problem motivates extending the SM electroweak (EW) 5D gauge symmetry in such a way that its breakdown to the SM delivers the SM Higgs boson. We study signals at the large hadron collider (LHC) for the extra EW (called coset) gauge bosons, a fundamental ingredient of this framework. The coset gauge bosons, due to their unique EW gauge quantum numbers [doublets of $SU(2{)}_L$], do not couple at leading order to two SM particles. We find that, using the associated production of the charged coset gauge bosons via their coupling to bottom quark and a (light) Kaluza-Klein excitation of the top quark, the LHC can have a $3\sigma$ reach of $\sim 2(2.6)\mathrm{TeV}$ for the coset gauge boson masses with $\sim 100(1000){\mathrm{fb}}^{-1}$ luminosity. Since current theoretical framework(s) suggest an indirect lower limit on coset gauge boson masses of $\gtrsim 3\mathrm{TeV}$, luminosity or energy upgrade of LHC is likely to be crucial in observing these states.

• Received 2 December 2009

DOI:https://doi.org/10.1103/PhysRevD.81.096002