Collider Implications of Kaluza-Klein Excitations of the Electroweak Gauge Bosons

Abstract

It is possible for the SM fields to propagate into one or more large extra compact dimensions. Such fields have associated KK excitations that produce additional contributions to the SM processes. We calculate the effects that these KK excitations have on cross sections for $e^{+}e^{-}$ collider processes in a model in which the SM gauge bosons, and perhaps the Higgs, can propagate into one TeV$^{-1}$-size extra compact dimension. Specifically, we consider muon pair production, Bhabha scattering, dijet production, Higgs production, and single-photon production. At prospective high energy $e^{+}e^{-}$ colliders, we find significant deviations from the SM cross sections: For example, a 600 GeV collider produces a 20% reduction in the cross section for muon pair production as compared to the SM for a compactification scale of 3.5 TeV. The effect is much smaller at LEP2 energies, where the compactification scale must be lower than 2 TeV in order to produce a 6% effect.