HIGGSLESS MODELS and DECONSTRUCTION

Abstract

We give a brief review on the deconstructed Higgsless models (linear moose models). The Fermi-constant GF and the low energy parameter are evaluated, and the physics behind the delay of unitarity violation is claried. In order to construct a viable model consistent with the precision electroweak data, lefthanded quarks and leptons need to be delocalized over the deconstructed extra dimension. We discuss \ideal delocalization of quarks and leptons with which deviations in precision electroweak parameters are minimized. As contributions to the S parameter vanish to leading order with the ideal delocalization, current constraints on these models arise from limits on deviations in triple gauge boson vertices. By using the block-spin transformation, we argue that low energy eectiv e theory of any consistent Higgsless model can be described by highly deconstructed linear moose model with only a fewer number of deconstructed sites. We propose the three-site model as the lowest order eectiv e theory of Higgsless models.