Parton energy loss in hot and dense QCD medium

Induced gluon radiation and energy loss of heavy quark in hot and dense QCD media are discussed. Using the light-cone path integral ap- proach, an analytical formula of the energy loss of heavy quark is derived. The results show that the quark energy loss obviously depends on the mass of quark, i. e. a remarkable suppression occurs in the case of heavy quark comparing to a light one. The radiative energy loss of energetic quark is propor- tional to L2, where L is the length of the medium. The dependence of energy loss on L2 turns to L with de- creasing quark energy.