"Table 163" of "Properties of jet fragmentation using charged particles measured with the ATLAS detector in $pp$ collisions at $\sqrt{s}=13$ TeV"

CERN-LHC. This paper presents a measurement of quantities related to the formation of jets from high energy quarks and gluons (fragmentation). Jets with $100$ GeV $ 500$ MeV~and $|\eta| < 2.5$~are used to probe the detailed structure of the jet. The fragmentation properties of the more forward and the more central of the leading two jets from each event are studied. The data are unfolded to correct for detector resolution and acceptance effects. Comparisons to parton shower Monte Carlo generators indicate that existing models provide a reasonable description of the data across a wide range of phase space, but there are also significant differences. Furthermore, the data are interpreted in the context of quark- and gluon-initiated jets by exploiting the rapidity dependence of the jet flavor fraction. A first measurement of the charged-particle multiplicity using model-independent jet labels (topic modeling) provides a promising alternative to traditional quark- and gluon- extractions using simulation input. The simulations provide a reasonable description of the quark-like data across the jet $p_\text{T}$ range presented in this measurement, but the gluon-like data have systematically fewer charged particles than the simulations. Uncertainties are broken down by category and should be treated as fully correlated between bins and between observables except for statistical uncertainties.

欧洲核子研究中心大型强子对撞机（CERN-LHC）。本文针对高能夸克与胶子喷注（jet）的形成相关物理量（碎裂过程）开展测量研究。选取横向动量$p_ ext{T}$介于100 GeV至500 GeV、赝快度$|eta| < 2.5$的喷注，用于探究喷注的精细结构。本文对每个事件中前导两喷注的更靠前向与更中心的喷注的碎裂特性展开研究。对实验数据进行去折叠校正，以修正探测器分辨与接收度效应带来的影响。与部分子喷注蒙特卡洛（parton shower Monte Carlo）发生器的比对结果显示，现有模型可在较宽相空间范围内合理描述实验数据，但仍存在显著差异。此外，本文借助喷注味组分的快度依赖性，将实验数据诠释为夸克初始与胶子初始喷注的相关结果。首次采用与模型无关的喷注标签方法（主题建模，topic modeling）测量带电粒子多重数，为替代传统基于模拟输入的夸克、胶子喷注甄别手段提供了极具前景的方案。模拟结果可在本次测量所覆盖的喷注横向动量范围内合理描述类夸克数据，但类胶子数据的带电粒子数系统性低于模拟结果。不确定性按类别划分，除统计不确定性外，各区间（bin）间与各观测量间的不确定性均视为完全相关。