Weak neutral currents in electron and muon scattering

Contributions to inelastic scattering arising from the interference of a weak neutral current with the electromagnetic current are calculated using the Weinberg model and the quark-parton model. These interferences produce nonvanishing (dσ⁻-dσ⁺), ($d{\sigma }^{-\left(L\right)}-d{\sigma }^{+\left(R\right)}$), ($d{\sigma }^{-\left(L\right)}-d{\sigma }^{-\left(R\right)}$), which give rise to sizable effects when compared to the purely electromagnetic scattering.