"Table 158" 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.

CERN-LHC。本论文报道了高能夸克（quark）与胶子（gluon）碎裂形成喷注（jet）相关物理量的测量结果。选取横向动量$p_ ext{T}$（transverse momentum）满足$100 ext{GeV} < p_ ext{T} < 500 ext{MeV}$且赝快度$eta$（pseudorapidity）的绝对值$|eta| < 2.5$的喷注，用于探究喷注的精细结构。本研究针对每个事件中前导双喷注内更靠前向与更中心的喷注的碎裂特性展开分析。为校正探测器分辨率与接收度效应，我们对数据进行了解卷（unfolding）处理。与部分子喷注蒙特卡洛（parton shower Monte Carlo）发生器的对比结果显示，现有模型可在较宽相空间范围内合理描述实验数据，但二者仍存在显著差异。此外，本研究利用喷注味组分的快度依赖性，将实验数据诠释为夸克引发与胶子引发的喷注。首次采用模型无关喷注标签（model-independent jet labels）结合主题建模（topic modeling）方法测量带电粒子多重数（charged-particle multiplicity），为传统上依赖模拟输入开展夸克与胶子喷注区分的方法提供了一种颇具前景的替代方案。模拟结果可在本次测量给出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。不确定度按类别划分，除统计不确定度外，各统计箱（bin）与各观测量间的不确定度均视为完全相关。