Beyond S, T, and U

The contribution to precision electroweak measurements due to TeV physics which couples primarily to the W± and Z bosons may be parametrized in terms of the three ‘‘oblique correction’’ parameters, S, T, and U. We extend this parametrization to physics at much lower energies, ≳100 GeV, and show that in this more general case neutral-current experiments are sensitive to only two additional parameters. A third new parameter enters into the W± …