Effects of neutral weak currents in e+-e− annihilation

The effects of neutral weak currents are discussed in e⁺e^? annihilation into final states such as μ⁺μ^?, e⁺e^?, π⁺π^?, many hadrons and also in the one particle inclusive production. According to current gauge models these weak effects which are manifested as various asymmetries, turn out to be around 10% in the energy range of PEP and PETRA. In identifying weak effects polarized incident beams are advantageous, in particular, the longitudinally polarized beams select parity violating asymmetries.