Kinetic theory of light-induced drift of particles with degenerate energy levels

Abstract
The theory of light-induced drift of particles with degenerate levels is proposed. Kinetic equations which are semiclassical with respect to rotational degrees of freedom and with a phase memory accounting are obtained. The drift velocity dependence on radiation polarisation is predicted. Numerical calculation, which has been made in a strong collision model, shows that the accounting of level degeneracy leads to a velocity change of up to 10-20% under some conditions.