Difermion Cross-sections At LEPII

Precision measurements at LEPII provide a unique test of Standard Model predictions. Re­sults from the four LEP collaborations ALEPH, DELPIII, L3 and OPAL on the difermion cross sections and asymmetries obtained at centre-of- mass energies between 192 and 202 GeV are presented. The high $s'$ results are used to determine the running of the electromagnetic coupling constant and the strength of the interference between photon and Z exchange. Due to the accuracy of both the data and the Standard Model predictions the measurements are also sensitive to deviations evoked by new physics. Since no significant deviations are observed, limits on contact interactions, and the exchange of sneutrino, leptoquark and Z' are set.