Parton Energy Loss at Twist-Six in Deeply Inelastic e-A Scattering
  Within the framework of the generalized factorization in pQCD, we investigate the multiple parton scattering and induced parton energy loss at twist-6 in deeply inelastic e-A scattering with the helicity amplitude approximation. It is shown that twist-6 processes will give rise to additional nuclear size dependence of the parton energy loss due to LPM interference effect while its contribution is power suppressed. 
Yun Guo, Ben-Wei Zhang, Enke Wang