# One-loop Corrections to the S Parameter in the Four-site Model - High Energy Physics - Phenomenology

Abstract: We compute the leading chiral-logarithmic corrections to the S parameter inthe four-site Higgsless model. In addition to the usual electroweak gaugebosons of the Standard Model, this model contains two sets of heavy charged andneutral gauge bosons. In the continuum limit, the latter gauge bosons can beidentified with the first excited Kaluza-Klein states of the W^\pm and Z bosonsof a warped extra-dimensional model with an SU2 L \times SU2 R \timesU1 X bulk gauge symmetry. We consider delocalized fermions and show that thedelocalization parameter must be considerably tuned from its tree-level idealvalue in order to reconcile experimental constraints with the one-loop results.Hence, the delocalization of fermions does not solve the problem of largecontributions to the S parameter in this class of theories and significantcontributions to S can potentially occur at one-loop.

Author: Sally Dawson, C.B. Jackson

Source: https://arxiv.org/