HIGH-PRECISION TESTS OF QED AND PHYSICS BEYOND THE STANDARD MODEL

We study the four most significant high precision observables of QED - the anomalous electron and muon magnetic moments, the hydrogen Lamb s hift, and muonium hyperfine splitting - in the context of SU(2) X U(1) gauge-invariant effective Lagrangians. The agreement between the theo retical predictions for these observables and the experimental data pl aces bounds on the lowest dimension operators of the effective Lagrang ians. We also place bounds on such effective operators using other exp erimental data. Comparison of the two types of bounds allows us to dis cuss the potential of each one of the four high precision observables in the search for physics beyond the Standard Model. We find that the anomalous electron and muon magnetic moments are sensitive to new phys ics while the hydrogen Lamb shift and muonium hyperfine splitting are not.