"Table 161" 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）。本研究针对高能夸克与胶子喷注的形成过程相关物理量开展测量。本研究选取横向动量$p_ ext{T}$介于100 GeV至500 GeV之间、带电粒子横向动量大于500 MeV且赝快度$|eta| < 2.5$的喷注，以探测喷注的精细结构。针对每个事件中前导双喷注内的更向前与更中心喷注的碎裂特性展开研究。对实验数据开展解卷处理，以修正探测器分辨率与接收度效应带来的影响。通过与部分子簇射（parton shower）蒙特卡洛（Monte Carlo）发生器进行对比后发现，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，但仍存在显著偏差。此外，本研究利用喷注味组分的快度依赖性，将实验数据归因于夸克初始喷注与胶子初始喷注的贡献。本研究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，为传统依赖模拟输入的夸克、胶子喷注甄别方法提供了极具前景的替代方案。蒙特卡洛模拟可在本测量涵盖的喷注横向动量范围内较好地描述类夸克喷注数据，但类胶子喷注数据的带电粒子多重数系统性低于模拟结果。本研究的不确定度按类别进行拆分，除统计不确定度外，各相空间分箱及各观测量间的不确定度均视为完全相关。