SM Kaluza-Klein Excitations and Electroweak Precision Tests

Abstract

We consider a minimal extension to higher dimensions of the Standard Model, having one compactified dimension, and we study its experimental tests in terms of electroweak data. We discuss tests from high-energy data at the $Z$-pole, and low-energy tests, notably from atomic parity violation data. This measurement combined with neutrino scattering data strongly restricts the allowed region of the model parameters. Furthermore this region is incompatible at 95% CL with the restrictions from high-energy experiments. Of course a global fit to all data is possible but the $χ^2_{\rm min}$ for degree of freedom is unpleasantly large.

LaTex, 14 pages, 2 figures. More refs. and one comment about the validity of our results for any number of extra dimensions added