We compute the azimuthal eccentricities arising from initial stage fluctuations in high energy proton-nucleus collisions at proper times $τ\geq 0^+$. We consider two sources of fluctuations, namely the geometrical structure of the proton and the fluctuation of color fields carried by both proton and nucleus. Describing these effects with Gaussian models allows us to analytically calculate the one- and two-point correlators of energy density, from which the eccentricities are obtained. We compute the proper time evolution of these quantities by approximating the Glasma dynamics in terms of linearized Yang-Mills equations, which we solve by assuming free field propagation and adopting the dilute-dense limit.
Influence of collective nuclear vibrations on initial state eccentricities in Pb+Pb collisions
在Monte Carlo Glauber模型下,研究了铅核集体量子效应对LHC能区Pb+Pb碰撞中方位各向异性系数$ε_{2,3}$的影响.考虑到量子效应,我们修改了采样的核子位置,通过应用适当的过滤器,保证碰撞核的均方四极矩和八极矩与提取的实验四极和八极强度函数的铅核的帮助下的能量加权和规则。我们的Monte Carlo Glauber模型与修改后的采样的核子位置导致$ε_2\{2\}/ε_3\{2\}\approx 0.8$在中心$\lesssim 1$ \%,这使得解决$v_2$ -到- $v_3$的难题。
Sensitivity of flow harmonics to sub-nucleon scale fluctuations in heavy ion collisions
本文采用一种新的平滑流体动力学初始能量密度的方法,证明了在核-核碰撞中,驱动末态流谐波$v_n$的初始空间偏心率$\varepsilon_{m,n}$对初始能量密度空间梯度的基本尺度$λ$的变化具有显著的鲁棒性。对于$\sqrt{s}=2.76$ TeV Pb+Pb碰撞,如果涨落的尺度从$0.1$变化到$1$ fm,则$\varepsilon_{m,n}$(跨中心性类)的变化小于$10\%$。我们表明,使用2+1拉格朗日流体动力学代码,v-USPhydro,这种鲁棒性被转移到最终的$v_n$的事件内计算事件粘性流体动力学。这表明核-核碰撞中的流谐波对限制尺度以下的潜在微观亚核子物理并不特别敏感。另一方面,顶部$1\%$高多重数$\sqrt{s}=5.02$ TeV p+Pb碰撞的偏心率被发现是非常敏感的亚核尺度的波动,这应该与具有相同的多重数的外围Pb+Pb碰撞中发现的鲁棒性形成对比。
Initial state geometry and the role of hydrodynamics in proton-proton, proton-nucleus and deuteron-nucleus collisions
我们将成功的重离子碰撞的Monte Carlo Glauber和IP-Mehma初态模型应用于质子-质子、质子-核和氘-核碰撞中产生的小得多的系统。我们观察到一个显着更大的灵敏度的初始状态的几何形状,在这些模型中的多粒子生产的细节相比,核-核碰撞。特别是,我们发现,在p+A碰撞中产生的系统的大小是非常相似的p+p碰撞中产生的,并预测可比的Hanbury-Brown-Twiss半径在两个系统中没有流动。模型中计算的偏心率差异较大,而生成的流量系数v_2和v_3之间的差异较小。对于大量的质子-铅碰撞的参与者,在IP-Plumma模型中产生的v_2值与质子-质子碰撞中获得的值相当。在较小尺寸的系统中,对流动的粘性修正在特征寿命上是大的。相反,粘性的贡献显着减少了较长的时空演化的重离子碰撞。
Neutron Skin Effects on Particle Emission in Heavy-Ion Collisions: A Topic Review with Astrophysical and Nuclear Structure Connections
Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Institute of Modern Physics, Fudan University(复旦大学现代物理研究所);Shanghai Research Center for Theoretical Nuclear Physics, NSFC and Fudan University(复旦大学理论核物理上海研究中心);School of Physics, East China Normal University(华东师范大学物理系)