论文标题
解开射流修改
Disentangling Jet Modification
论文作者
论文摘要
重型离子碰撞中的喷气式修饰是对这些碰撞中产生的夸克 - 胶子等离子体(QGP)的性质和结构的重要探针,还编码有关如何以QGP形式滴注并放松的唤醒者如何激发唤醒的信息。但是,在实验中,人们不知道在不淬火的情况下,重离子碰撞中的特定喷射会是什么样子,这使得很难用单个喷气机修改来解释测量值。这项蒙特卡洛研究的目的是使用杂交强/弱耦合模型作为测试床来深入了解射流可观察物的修饰。在这项蒙特卡洛研究(但不是在实验中),可以观看$ \ textit {相同的喷射} $与真空或QGP中演变的相同。我们使用这种能力来解开重离子碰撞中单个喷气机的修饰的影响,而不同选择偏见对两个可观察到的分布的影响:分数能量损失和修饰$ΔR$。我们发现,在混合模型中,在淬灭后选择的喷气机样品中,修饰$ΔR$的分布似乎未被修饰,就像在重离子碰撞中一样,并确认由于对喷气机的选择偏差仅损失了一小部分能量,因此出现了这种缺乏修改。相反,如果我们以避免这种偏见的方式选择喷气机,然后在淬火时遵循这些选定的喷气机,我们表明实际上对单个喷气机的$ΔR$进行了实质性的修改。我们表明,这种射流的修饰主要是由于颗粒掺入了来自等离子体中的Parton淋浴兴奋的颗粒,作为实验者重建为喷气的组成部分的组成部分。我们讨论的效果在大小上是很大的,这表明我们的定性结论比我们获得的蒙特卡洛研究更一般。
Jet modification in heavy-ion collisions is an important probe of the nature and structure of the quark-gluon plasma (QGP) produced in these collisions and also encodes information about how the wakes that jets excite in a droplet of QGP form and relax. However, in experiment, one cannot know what a particular jet in a heavy ion collision would have looked like without quenching, making it difficult to interpret measurements in terms of individual jet modification. The goal of this Monte Carlo study is to gain insight into the modification of jet observables using the hybrid strong/weak coupling model of jet quenching as a test bed. In this Monte Carlo study (but not in experiment) it is possible to watch $\textit{the same jet}$ as it evolves in vacuum or in QGP. We use this ability to disentangle the effects of modification of individual jets in heavy ion collisions vs. the effects of differing selection bias on the distribution of two observables: fractional energy loss and groomed $ΔR$. We find that in the hybrid model the distribution of groomed $ΔR$ appears to be unmodified in a sample of jets selected after quenching, as in heavy ion collisions, and confirm that this lack of modification arises because of a selection bias toward jets that lose only a small fraction of their energy. If instead we select jets in a way that avoids this bias, and then follow these selected jets as they are quenched, we show that there is, in fact, a substantial modification of the $ΔR$ of individual jets. We show that this jet modification is principally due to the incorporation of particles coming from the wake that the parton shower excites in the plasma as a component of what an experimentalist reconstructs as a jet. The effects we discuss are substantial in magnitude, suggesting that our qualitative conclusions are more general than the Monte Carlo study in which we obtain them.