Gluon Emission of Heavy Quarks: Dead Cone Effect
  The lowest-order induced soft gluon radiation processes of heavy quarks have been analyzed to quantify the dead cone effect. This effect is most likely expected to suppress significantly the energy loss of charm quarks passing an amorphous color-neutral deconfined medium, as has been concluded from recent experiments at RHIC. 
R. Thomas, B. Kampfer, G. Soff