Quark aspects of parity nonconservation in nucleon systems

Two approaches to the effects of parity nonconservation (PNC) in nucleon systems; the potential ones based on the meson representation of nuclear forces and the quark-nuclear one wich an NN-system at short distances is represented as a multiquark association are analysed and compared. The aim of the review is as follows: to clarify a theoretical basis of the study of the complicated phenomenon, the PNC in NN-interactions on the modern quark level and to expound the corresponding formalisms; to show that the standard electroweak model with including colour intractions between quarks (QCD) is a realistic ground for describing the PNC effects in NN-systems and nuclei at low energies; to demonstrate that more accurate experimental data will make it possible to determine important characteristics in gauge theories and to promote further development of ideas on nuclear forces