Spin Effects in Two Quark System and Mixed States

Based on the numeric solution of a system of coupled channels for vector mesons (S-and D-waves mixing)and for tensor mesons (P- and F- waves mixing) mass spectrum and wave functions of a family of vector mesons q in triplet states a e obtained. The calculations are performed using a well-known Cornell potential with a mixed Lorentz- structure of the confinement term. The spin-dependent part of the potential is taken from the Breit-Fermi approach.The effect of irregular terms of the potential is considered within the framework of the perturbation theory and/or of the configuration interaction approach, modified for a system of coupled equations. It is shown that even a small integral contribution of the D-wave to the total wave function of q system is very impotant for the calculation of certain characteristics of the meson states.