The rapidity dependence of the elliptic flow of direct photons in Au＋Au collisions at√ s NN = 200 GeV are predicted,based on a three-dimensional ideal hydrodynamic description of the hot and dense matter.The rapidity dependence of the elliptic flow v 2 （y） of direct photons （mainly thermal photons） is very sensitive to the initial energy density distribution along longitudinal direction,which provides a useful tool to extract the realistic initial condition from measurements.
Jet quenching has been proposed as a probe of the properties of the strongly interacting quarkgluon-plasma in high energy heavy ion collisions.At the meantime,it is also important to study the excitation of medium by propagating jets.Based on Boltzmann equation,a Monte Carlo was constructed to simulate the elastic collisions with thermal partons by energetic jets.Medium modification due to jet-medium interaction has been studied within this model in a uniform medium.
