Supersymmetry and precision data after LEP2

We study one loop supersymmetric corrections to precision observables. Adding LEP2 ee¯→ff¯ cross sections to the data-set removes previous hints for SUSY and the resulting constraints are in some cases stronger than direct bounds on sparticle masses. We consider specific models: split SUSY, CMSSM, gauge mediation, anomaly and radion mediation. Beyond performing a complete one-loop analysis, we also develop a simple approximation, based on the Sˆ,Tˆ,W,Y 'universal' parameters. SUSY corrections give W,Y>0 and mainly depend on the left-handed slepton and squark masses, on M2 and on μ.