Hadron freeze-out conditions in high energy nuclear collisions

摘要: Systematic trend of the hadron freeze-out conditions from AGS/SPS to RHIC is discussed. The most interesting results collisions at are that system indeed approaching net-baryon free and transverse expansion much stronger than energies. In order understand collective velocity, an energy scan between $\sqrt{s_{NN}} = 20 - 200 GeV, important. addition, systematic studies on anisotropy parameter $v_2$ momentum distributions $\phi, \Omega,$ $J / \psi$ necessary as they will help in determining whether collectivity developed partonic stage.