Electroweak-ons Meet Electroweak Precision

The universality of the Standard Model fermion couplings to the W and Z ensure that they are the massive gauge bosons of a spontaneously broken SU(2) x U(1) symmetry. However the mechanism responsible for the spontaneous break down of electroweak symmetry may be more complicated than the single scalar doublet of the Standard Model. While we have no direct evidence of new physics which takes part in electroweak symmetry breaking, naturalness hints at new physics above the electroweak scale and many models which address the hierarchy problem often have additional Higgs fields. With this in mind, I will discuss generic extensions of the Higgs sector and constraints from electroweak precision parameters.