Discriminating between Z′-boson effects and effects of anomalous gauge couplings in the double production of W± bosons at a linear collider

The potential of the International Linear electron-positron Collider (ILC) for seeking, in the annihilation production of W±-boson pairs, signals induced by new neutral gauge bosons predicted by models belonging to various classes and featuring an extended gauge sector is studied. Limits that will be obtained at ILC for the parameters and masses of Z′ bosons are compared with present-day and future data from the Large Hadron Collider (LHC). The possibility of discriminating between the effects of Z-Z′ mixing and signals induced by anomalous gauge couplings (AGC) is demonstrated within theoretically motivated trilinear gauge models involving several free anomalous parameters. It is found that the sensitivity of ILC to the effects of Z-Z′ mixing in the process e+e− → W+W− and its ability to discriminate between these two new-physics scenarios, Z′ and AGC, become substantially higher upon employing polarized initial (e+e−) and final (W±) states.