Gluon Radiation off Massive Quarks in a QCD Medium
  Medium-induced gluon radiation from massless and massive quarks is treated in the same formalism. The dead cone which regulates gluon radiation from massive quarks in the vacuum at small angles, is filled in the medium but constitutes a small fraction of the available phase space. Our study indicates that the energy loss for charmed hadrons at RHIC should be smaller than for light hadrons, but still sizable. 
N. Armesto, C. A. Salgado and U. A. Wiedemann