论文标题
在重离子碰撞中探测撞击参数依赖性的核部分密度
Probing impact-parameter dependent nuclear parton densities from double parton scatterings in heavy-ion collisions
论文作者
论文摘要
我们提出了一种新方法，以使用高能重型离子（Proton-Nucleus and Nucleus nucleus）碰撞中的双Parton散射（DPS）过程来确定空间或影响参数依赖性核部分分布函数（NPDFS）。在假设NPDF的冲击参数依赖性仅与核厚度函数有关的假设下，我们通过容纳核碰撞几何形状和空间依赖的核修饰效应来得出一个简单的通用DPS公式。尽管几何效应被广泛采用，但到目前为止，在空间依赖的核修饰对DPS横截面的影响已经被忽略了，但是，当初始核修饰较大时，这可能会很重要。反过来，重离子碰撞中的DPS横截面可以提供有关NPDF的空间依赖性的有用信息。通常，它们可以在最小偏置的核碰撞中获得，其优点是格劳伯建模的独立性。
We propose a new method to determine the spatially or impact-parameter dependent nuclear parton distribution functions (nPDFs) using the double parton scattering (DPS) processes in high-energy heavy-ion (proton-nucleus and nucleus-nucleus) collisions. We derive a simple generic DPS formula in nuclear collisions by accommodating both the nuclear collision geometry and the spatially dependent nuclear modification effect, under the assumption that the impact-parameter dependence of nPDFs is only related to the nuclear thickness function. While the geometric effect is widely adopted, the impact of the spatially dependent nuclear modification on DPS cross sections has been overlooked so far, which can, however, be significant when the initial nuclear modification is large. In turn, the DPS cross sections in heavy-ion collisions can provide useful information on the spatial dependence of nPDFs. They can be, in general, obtained in minimum-bias nuclear collisions, featuring the virtue of independence of Glauber modeling.
