Supersymmetry and Electroweak Leptonic Observables

We study vertex corrections to the leptonic electroweak observables in the general MSSM at tan(beta) < 35. In particular, we address the question of whether supersymmetry can be responsible for the observed 2 sigma deviation from the Standard Model prediction in the invisible width of the Z. We find that the presence of a light (around 100 GeV) chargino and sleptons hinted by the muon g-2 measurements makes the agreement with experiment slightly better and improves the electroweak fit.