Physics Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
Phys Rev Lett. 2012 Jun 22;108(25):252301. doi: 10.1103/PhysRevLett.108.252301. Epub 2012 Jun 18.
We compute initial conditions in heavy ion collisions within the color glass condensate framework by combining the impact parameter dependent saturation model with the classical Yang-Mills description of initial Glasma fields. In addition to fluctuations of nucleon positions, this impact parameter dependent Glasma description includes quantum fluctuations of color charges on the length scale determined by the inverse nuclear saturation scale Q(s). The model naturally produces initial energy fluctuations that are described by a negative binomial distribution. The ratio of triangularity to eccentricity ε(3)/ε(2) is close to that in a model tuned to reproduce experimental flow data. We compare transverse momentum spectra and v(2,3,4)(p(T)) of pions from different models of initial conditions using relativistic viscous hydrodynamic evolution.
我们通过将依赖于碰撞参数的饱和模型与初始 Glasma 场的经典杨-米尔斯描述相结合,在色玻璃凝聚态框架内计算重离子碰撞中的初始条件。除了核子位置的涨落外,这种依赖于碰撞参数的 Glasma 描述还包括由核子饱和标度 Q(s)的倒数确定的长度尺度上的颜色电荷的量子涨落。该模型自然产生了由负二项式分布描述的初始能量涨落。三角形度与偏心率之比 ε(3)/ε(2)接近一个被调整为重现实验流数据的模型的值。我们使用相对论粘性流体力学演化比较了来自不同初始条件模型的介子的横向动量谱和 v(2,3,4)(p(T))。