A novel approach to confront electroweak data and theory

Observability of the neutrino charge radius

It is shown that the probe-independent charge radius of the neutrino is a physical observable; as such, it may be extracted from experiment, at least in principle. This is accomplished by expressing a set of experimental nu(mu)-e cross sections in terms of the finite charge radius and two additional gauge- and renormalization-group-invariant quantities, corresponding to the electroweak effective charge and mixing angle.

Light bottom squark and gluino confront electroweak precision measurements

We address the compatibility of a light sbottom (mass approximately 2-5.5 GeV) and a light gluino (mass approximately 12-16 GeV) with electroweak precision measurements. Such light particles have been suggested to explain the observed excess in the b quark production cross section at the Tevatron. The electroweak observables may be affected by the sbottom and gluino through the supersymmetric-QCD (SUSY-QCD) corrections to the Zbb vertex. We examine, in addition to the SUSY-QCD corrections, the gauge boson propagator corrections from the stop which are allowed to be light from the SU(2)(L) symmetry. We find that this scenario is strongly disfavored from electroweak precision measurements.