Extra neutral gauge bosons (Z) are predicted in many extensions of the Standard Model (SM). In the minimal anomaly-free Z model (AFZ), the phenomenology is controlled by only three parameters beyond the SM ones, the Z mass and two effective coupling
constants g_Y and g_{BL}. We study the Z 5-sigma discovery potential in e+e- collisions at 1.4 and 3 TeV CLIC. Assuming LHC discovers a Z of 5 TeV mass, the expected accuracies on the Zmu+mu- couplings are presented. We discuss also the requirements on detector performance and beam polarization.
We present a model of electroweak symmetry breaking in a warped extra dimension where electroweak symmetry is broken at the UV (or Planck) scale. An underlying conformal symmetry is broken at the IR (or TeV) scale generating masses for the electrowea
k gauge bosons without invoking a Higgs mechanism. By the AdS/CFT correspondence the W,Z bosons are identified as composite states of a strongly-coupled gauge theory, suggesting that electroweak symmetry breaking is an emergent phenomenon at the IR scale. The model satisfies electroweak precision tests with reasonable fits to the S and T parameter. In particular the T parameter is sufficiently suppressed since the model naturally admits a custodial SU(2) symmetry. The composite nature of the W,Z-bosons provide a novel possibility of unitarizing WW scattering via form factor suppression. Constraints from LEP and the Tevatron as well as discovery opportunities at the LHC are discussed for these composite electroweak gauge bosons.
