Neutral-current effects in the standard and extended gauge models for spin polarization effects in e+e- → μ+μ-Эффекты нейтральных токов в стандартной и обобщенной калибровочных моделях для спиновых поляризационных эффектов в е+e-→ μ+μ-

We study various observables (the asymmetry due to the beam polarizations, the forward-backward asymmetry, etc.) in which the neutral-current effects appear in the reaction e+e- →μ+μ- induced by (longitudinally and transversely) polarized as well as unpolarized e+e- beams in combination with the measurements of the longitudinal polarizationPL(μ-) of the outgoing muon(s). We carry out the numerical calculation for these quantities at TRISTAN and LEP energies, adopting as examples of the electroweak gauge models the standard WeinbergSalam model, the ones based onSU2× U1×[U1]′ and onSU2× U1 ×[SU2]′. We argue that at TRISTAN energies the angular distribution of PL(μ-) measurable in the experiment by the polarized beams is especially useful for the purpose of distinguishing between the models. At LEP energy range the measurements of the angular distribution and the energy dependence of PL(μ-) using polarized beams, in addition to the measurement of the total cross-section, can determine the correct model if any.