Z' and anomalous gauge coupling effects at LEP2 and their separation
  In the case of the process $e^+e^-\to\mu^+\mu^-$, we study the sensitivity to either $Z^\prime$ or anomalous gauge coupling effects of two new observables, $\sigma_+$ and $\sigma_-$, conveniently defined for such kind of analysis. We discuss general properties of the deviations of these observables from the Standard Model predictions, and derive the model-independent bounds on the relevant parameters allowed by present and foreseeable LEP2 data. We also discuss the possibility of separating the two kinds of effect. 
A. A. Babich, A. A. Pankov (Gomel), N. Paver (Trieste)