Radiative corrections and electroweak observables

Different electroweak observables probe different combinations of the parameters θ¯ (the weak mixing angle as defined in terms of couplings at the Z pole) and ρ==${\mathit{M}}_{\mathit{W}}^2$/(${\mathit{M}}_{\mathit{Z}}^2$ ${\cos }^2$θ¯). A simple, approximate method is given for relating these parameters to the angle θ defined in terms of gauge-boson masses by ${\cos }^2$θ${\mathit{ieqM}}_{\mathit{W}}^2$/${\mathit{M}}_{\mathit{Z}}^2$, and it is shown how these various observables shed light on θ and quantities such as the top-quark mass that directly affect ρ.