Assessing saturation physics explanations of collectivity in small collision systems with the ip-jazma model
Assessing saturation physics explanations of collectivity in small collision systems with the ip-jazma model
复制标题
使用 ip-jazma 模型评估小型碰撞系统中集体的饱和物理解释
DOI：
10.1103/physrevc.99.054908
复制
发表时间：
2018
影响因子：
3.1
通讯作者：
W. Zajc
中科院分区：
文献类型：
--
作者：
J. Nagle;W. Zajc
在RHIC和LHC上对从p+p到p/d/3 He +A的小系统碰撞的实验测量揭示了与A+A碰撞中观察到的粒子发射模式惊人相似的粒子发射模式。对这些模式的一种解释是夸克胶子等离子体的小液滴的形成，随后是流体动力学演化。提出了一个几何工程程序[1]来研究这些发射模式，并且该程序在p+Au，d+Au，3 He +Au碰撞中的椭圆和三角各向异性系数v2和v3的实验数据符合流体动力学计算预测的模式[2]。另一种被称为初始态关联的方法表明，对于小系统，在末态强子中观察到的模式在碰撞的最早时刻被编码，因此不需要末态部分子散射或流体动力学演化[3，4]。最近，在胶子饱和物理的稀密近似下，仅使用初态关联的新计算报告与RHIC的p/d/3 He +Au数据中观察到的v2模式惊人地一致[5]。报告的结果是违反直觉的，因此我们的目标是在这里重现这些计算的一些基本特征。在这第一次调查中，我们提供了一个描述我们的模型，IP-Jazma，并调查其影响的饱和度尺度，多重性分布和偏心率，为以后的工作保留动量谱和方位角各向异性的分析。我们发现，我们的饱和物理模型的实现再现的d+Au碰撞在RHIC的多重数分布的早期计算的结果。然而，我们的调查以及现有数据对参考文献[5]中报告的一些基本要素提出了质疑。
Experimental measurements in collisions of small systems from p+p to p/d/3He+A at RHIC and the LHC reveal particle emission patterns that are strikingly similar to those observed in A+A collisions. One explanation of these patterns is the formation of small droplets of quark-gluon plasma followed by hydrodynamic evolution. A geometry engineering program was proposed [1] to investigate these emission patterns, and the experimental data from that program in p+Au, d+Au, 3He+Au collisions for elliptic and triangular anisotropy coefficients v2 and v3 follow the pattern predicted by hydrodynamic calculations [2]. One alternative approach, referred to as initial-state correlations, suggests that for small systems the patterns observed in the final-state hadrons are encoded at the earliest moments of the collision, and therefore require no final-state parton scattering or hydrodynamic evolution [3,4]. Recently, new calculations using only initial-state correlations, in the dilute-dense approximation of gluon saturation physics, reported striking agreement with the v2 patterns observed in p/d/3He+Au data at RHIC [5]. The reported results are counterintuitive and thus we aim here to reproduce some of the basic features of these calculations. In this first investigation, we provide a description of our model, IP-Jazma, and investigate its implications for saturation scales, multiplicity distributions and eccentricities, reserving for later work the analysis of momentum spectra and azimuthal anisotropies. We find that our implementation of the saturation physics model reproduces the results of the earlier calculation of the multiplicity distribution in d+Au collisions at RHIC. However, our investigations, together with existing data, call into question some of the essential elements reported in Ref. [5].
影响因子：
19.6
作者：
Aidala, C.;Akiba, Y.;Zou, L.
通讯作者：
Zou, L.