| We study deconstructed Higgsless models of electroweak symmetry breaking. As the name implies, these models break electroweak symmetry without the presence of a scalar Higgs boson in the spectrum. These models are inspired by compactified extra dimensional models, where the WLWL scattering amplitude is unitarized by a tower of new, heavy vector bosons in place of the Higgs. We study a simplified theory with only one set of extra vector bosons and derive the wavefunctions and couplings in this theory. We then extend this model to include a "top-Higgs" link, so as to separate the top quark mass generation from the rest of electroweak symmetry breaking, which still goes through via a Higgsless mechanism. This enables us to have new, heavy Dirac fermions that are light enough to be discovered at the LHC. We present the phenomenology of these heavy fermions, showing that they are discoverable at the 5sigma level at the LHC for a wide range of masses. Finally, we move on to consider the question of unitarity and the heavy Dirac fermion mass generation by investigating the process tt¯ → W+LW-L in a family of deconstructed Higgsless models, and show how the Appelquist-Chanowitz bound can be substantially weakened for sufficiently light Dirac fermions. |
