"Table 28" of "Measurements of observables sensitive to colour reconnection in $t\bar{t}$ events with the ATLAS detector at $\sqrt{s}=13$ TeV"

- CERN-LHC. A measurement of observables sensitive to effects of colour reconnection in top-quark pair-production events is presented using $139~\text{fb}^{-1}$ of 13 TeV proton--proton collision data collected by the ATLAS detector at the LHC. Events are selected by requiring exactly one isolated electron and one isolated muon with opposite charge and two or three jets, where exactly two jets are required to be $b$-tagged. For the selected events, measurements are presented for the charged-particle multiplicity, the scalar sum of the transverse momenta of the charged particles, and the same scalar sum in bins of charged-particle multiplicity. These observables are unfolded to the stable-particle level, thereby correcting for migration effects due to finite detector resolution, acceptance and efficiency effects. The particle-level measurements are compared with different colour reconnection models in Monte Carlo generators. These measurements disfavour some of the colour reconnection models and provide inputs to future optimisation of the parameters in Monte Carlo generators.

本文利用欧洲核子研究中心（CERN）的大型强子对撞机（Large Hadron Collider, LHC）上ATLAS探测器采集的13 TeV质子-质子对撞数据集（积分亮度139 fb⁻¹），报告了顶夸克对产生事件中对色重连效应敏感的可观测量的测量结果。事件筛选要求恰好包含一个孤立电子、一个带相反电荷的孤立μ子，以及2或3个喷注，且其中恰好2个喷注需被标记为b喷注。针对筛选得到的事件，本文报告了带电粒子多重数、带电粒子横向动量标量和，以及按带电粒子多重数分箱后的该标量和的测量结果。将这些可观测量展开至稳定粒子层面，从而修正由有限探测器分辨率、接受度和效率效应导致的迁移效应。将粒子层面的测量结果与蒙特卡洛发生器中的不同色重连模型进行对比。本测量结果对部分色重连模型给出了排除性约束，并可为未来蒙特卡洛发生器的参数优化提供输入依据。