高能重离子碰撞中的横向非对称流

Anisotropic Transverse Flow in High Energy Heavy Ion Collisions

对末态粒子方位角分布的研究可以获得反应中有关横向非对称流的信息 .研究了碰撞中侧向流与椭圆流间的方位角关联 ,给出了一种定量测量反应中椭圆流大小的方法 。

The anisotropy of the azimuthal distributions of the final state particles from nucleus nucleus collisions is studied within the microscopic transport approach. A clear signature of the azimuthal correlation between directed and elliptic flow is evidenced in the model calculations. It is found that the azimuthal correlation is sensitive to the magnitude and type of transerves flow. The second Fourier coefficients of the azimuthal distribution can be calculated on an event by event basis. In order to obtain a statistically relevant measurement, the elliptic flow of the collisions can be determined by further averaging over many events. Using this method of analysis, the influence of the azimuthal dispersion of the estimated reaction plane to the measured results of elliptic flow can be removed.