"Table 143" 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。本研究针对高能夸克与胶子引发的喷注（jet）形成相关物理量开展测量，即喷注碎裂（fragmentation）研究。选取横向动量$p_ ext{T}$满足$100, ext{GeV} < p_ ext{T} < 500, ext{GeV}$且赝快度$|eta| < 2.5$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。为校正探测器分辨与接收度效应，对实验数据进行解卷处理。将本测量结果与部分子簇射（parton shower）蒙特卡洛发生器（Monte Carlo generator）的模拟结果对比后发现，现有模型可在较宽相空间范围内合理描述实验数据，但二者间仍存在显著差异。

进一步，本研究利用喷注味组分的快度（rapidity）依赖性，将实验数据按夸克起源喷注（quark-initiated jet）与胶子起源喷注（gluon-initiated jet）进行归类。首次采用无模型依赖的喷注标签方法（主题建模（topic modeling））测量带电粒子多重数（charged-particle multiplicity），为替代传统基于模拟输入的夸克与胶子喷注区分方法提供了极具前景的新思路。模拟结果可合理描述夸克类喷注在本次测量覆盖的喷注横向动量区间内的分布，但胶子类喷注的带电粒子多重数系统性低于模拟结果。

不确定度按类别拆分，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。