Authors: Bingbing Wang (CSPAR), Gary Zank (CSPAR,UAH), Laxman Adhikari (CSPAR,UAH)

It is well-known that the drift due to the irregular magnetic field plays an important role in the transport process of solar energetic particles and cosmic rays. The widely adopted classical drift coefficient works for very weak turbulent magnetic fields. It is not satisfied either from the view of theory considering the solar wind, the turbulence is not so weak, nor from the studies of solar modulation of cosmic ray fluxes.
Stawicki et al. (2005) first applied the quasi-linear theory (QLT) to investigate the drift coefficient caused by the turbulent electromagnetic field. We extend this model by involving the high order terms that were ignored in the Stawicki model. The extended model provides a refined theoretical framework for calculating the drift coefficient and corresponding drift velocity in the turbulent solar wind. This provides a possible theoretical explanation for the suppression of the drift velocity found in solar modulation studies.