Simple model for description of spin crisis

It is shown that, owing to pion and kaon (η-meson) emission during the initial stage of evolution (from q2∼Mquark2 to q2∼1 GeV2), the major fraction of the proton spin that is initially determined by the wave function of additive quarks in the SU(6) model can be converted into the orbital angular momentum of pseudoscalar mesons. The results of calculations are in good agreement with experimental data. In the same model, violation of the Gottfried sum rule is explained by charged-meson emission. The Gribov-Lipatov relation between the structure functions of polarized particles in e+e- annihilation and deep-inelastic scattering is discussed. This makes is possible to study experimentally the spin structure of the Λ hyperon produced in the fragmentation of quark jets