"Table 3" 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）。本文报道了一项针对高能夸克与胶子喷注碎裂（jet fragmentation）形成相关物理量的测量研究。选取横向动量$p_ ext{T}$介于100 GeV至500 GeV之间、喷注内带电粒子横向动量大于500 MeV且赝快度$|eta| < 2.5$的喷注，用以探究喷注的精细结构。本文对每个事件中前两喷注里更靠前向与更中心的喷注的碎裂性质展开研究。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影响。与部分子簇射（parton shower）蒙特卡洛发生器的对比结果显示，现有模型在宽泛的相空间范围内能够合理描述实验数据，但同时也存在显著差异。此外，通过利用喷注味组分的快度依赖关系，我们将数据按夸克初始与胶子初始喷注的框架进行解读。首次采用无模型依赖的喷注标签方法（topic modeling，主题建模）对带电粒子多重数进行测量，为替代传统依靠模拟输入提取夸克与胶子喷注特性的方案提供了极具前景的新途径。模拟结果能够合理描述本测量中所覆盖喷注横向动量区间内的类夸克数据，但类胶子数据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，各区间与各可观测量之间的不确定度均视为完全相关。