中能重离子反应中的在平面流和椭圆流

Directed and Elliptic Flow in Heavy Ion Collisions

利用同位旋相关的量子分子动力学模型研究了40 Ca + 40 Ca系统在能量从3 0MeV/u到 1 50MeV/u的在平面流和椭圆流 .发现随着入射能量的增加 ,在平面流出现从负到正的跃迁 ,而椭圆流则随入射能量的增大而减少并且出现从正到负的跃迁 .椭圆流和在平面流对于入射能量和碰撞参数较为敏感 ,相反对于对称能和核态方程却不太敏感 .

The directed and elliptic flow in collisions of 40Ca+ 40Ca at energies from 30MeV/nucleon to 150MeV/nucleon is well studied in an isospin-dependent quantum molecule dynamics model (IQMD). With increasing incident energy, the directed flow rises from the negative to the positive and the elliptic flow shows decrease with increasing incident energy. The directed flow and the elliptic flow are sensible of the impact parameter and incident energy but they are not very sensible of systematic energy. The directed flow and the elliptic flow are also not very sensible of the EOS because of the combined systematic mass. Systematic studies of the cluster mass dependence are also carefully performed and the elliptic flow of heavy cluster mass is larger than that of light cluster mass. The difference of elliptic flow between the heavy cluster mass and the light one will be not very obvious with increasing incident energy because of large number of light cluster mass.