"Table 1" 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）：本文报道了高能夸克与胶子喷注碎裂（fragmentation）过程相关物理量的测量结果。本研究选取横向动量$p_ ext{T}$介于100 GeV至500 GeV、快度$|eta| < 2.5$的喷注，以探究喷注的精细内部结构。针对每个事件中的领头双喷注，本文分别对其更靠近向前快度区与更靠近中心快度区的喷注的碎裂特性展开研究。对实验数据进行展开校正，以修正探测器分辨效应与接收度效应带来的系统偏差。通过与部分子喷注（parton shower）蒙特卡洛发生器（Monte Carlo generators）的比对可知，现有模型可在较宽相空间范围内合理描述实验数据，但仍存在显著偏差。此外，本文利用喷注味组分占比的快度依赖性，将实验数据按夸克起源与胶子起源喷注进行分类解读。本文首次采用模型无关喷注标签结合主题建模（topic modeling）的方法测量带电粒子多重数，为摆脱模拟输入依赖的传统夸克、胶子组分提取手段提供了极具前景的替代方案。蒙特卡洛模拟可在本次测量覆盖的喷注横向动量区间内合理描述类夸克数据，但类胶子数据的带电粒子多重数系统性低于模拟结果。不确定性按类别拆分，除统计不确定性外，各数据分箱间与各观测量间的不确定性均视为完全相关。