Jet quenching of massive quarks in a nuclear medium
  Utilizing the generalized factorization of twist-4 processes, we derive the modified heavy quark fragmentation function after considering the gluon radiation induced by multiple scattering in DIS. It is found that the mass effects of heavy quark may reduce the gluon formation time and change the medium size dependence of heavy quark energy loss. The radiative energy loss is also significantly suppressed relative to a light quark due to the dead-cone effect. 
Ben-Wei Zhang