"Table 74" 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）数据集。本论文针对高能夸克与胶子碎裂形成喷注（jet）相关物理量展开测量研究。本研究选取横向动量（$p_ ext{T}$）满足$100 ext{GeV} < p_ ext{T} < 500 ext{GeV}$、赝快度$|eta| < 2.5$的喷注，用于探究喷注的精细结构。针对每个事件中领头双喷注里更靠前向与更中心的喷注的碎裂特性开展分析。对实验数据进行去折叠处理，以修正探测器分辨与接收度效应带来的系统偏差。通过与部分子级联（parton shower）蒙特卡洛发生器的比对可知，现有模型可在较宽相空间范围内对实验数据给出合理描述，但二者间仍存在显著差异。此外，本研究借助喷注味组分的快度依赖特性，将实验数据诠释为夸克初始喷注与胶子初始喷注的混合样本。首次采用与模型无关的喷注标记方法（主题建模，topic modeling）对带电粒子多重数开展测量，为替代传统依赖模拟输入的夸克、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给出的喷注横向动量区间内对类夸克数据给出合理描述，但类胶子数据的带电粒子多重数系统性低于模拟预言值。不确定度按类别拆分，除统计不确定度外，各分箱区间与各观测量间的不确定度均视为完全相关。