高能重离子对撞是核物理与粒子物理的前沿热点之一，其最主要的目的是寻找QGP（夸克胶子等离子体）存在的证据以及研究QGP的性质。在高能重离子碰撞中，J/ψ产额的压低（由于QGP中的"色屏蔽"的效应，造成J/ψ在QGP中的消融）被认为是QGP产生的最标志性的信号之一。但是除了"色屏蔽"的效应外，J/ψ在QGP中的"再产生"（在QGP中，不关联的粲夸克以及反粲夸克重新结合，形成J/ψ）以及冷核效应(例如：部分子分布函数在原子核中相对于质子中的改变，色玻璃凝聚效应，初始能量损失，多次散射，核子吸收效应等等)也会对J/ψ的产额和动力学特性产生影响。利用RHIC(相对论重离子对撞机，位于美国纽约长岛布鲁克海文国家实验室)STAR的实验数据，测量在不同对撞能量、对撞系统和中心度下J/ψ的产额和极化，对于研究J/ψ的产生机制、了解QGP的性质具有重要的科学意义。

High energy heavy ion collision is one of the major frontiers in nuclear and particle physics. The main goal of high energy heavy ion collision is to find the existence of QGP (Quark-Gluon Plasma) and to study its properties. The suppression of J/ψ production in heavy ion collisions (due to the color charge screening, the J/ψ would melt in QGP) has been proposed as a “smoking gun” signature of the formation of QGP. But, in addition to the effect of color charge screening, the J/ψ production and kinematics would also be modified by the regeneration of J/ψ (recombination from uncorrelated charm quarks) and the cold nuclear matter effects (such as the modification of parton distribution functions, color glass condensate, initial energy loss, multiple scatterings, and nuclear absorption). Thus the measurements of J/ψ invariant yield and polarization in different collision energies, different collision systems, and different centralities at RHIC (Relativistic Heavy Ion Collider, locate at Brookhaven National Laboratory, USA) STAR would shed new light on the interplay of J/ψ production mechanisms and QGP properties.