Neutral-current effects in the standard and extended gauge models for spin polarization effects in e+e-→μ+μ-

They are studied 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 unpolarized e+e- beams in combination with the measurements of the longitudinal polarization Psub(L)(μ-) of the outgoing muon(s). It is carried out the numerical calculation for these quantities at TRISTAN and LEP energies, adopting as examples of the electroweak gauge models the standard Weinberg-Salam model, the ones based on SU2xU1x[U1] 'and on SU2xU1x[SU2]'. It is argued that at TRISTAN energies the angular distribution of Psub(L)(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 Psub(L)(μ-)using polarized beams, in addition to the measurement of the total cross-section, can determine the correct model if any