"Table 59" of "Measurement of differential cross sections for the production of top quark pairs and of additional jets in lepton+jets events from pp collisions at $\sqrt{s} =$ 13 TeV"

Differential and double-differential cross sections for the production of top quark pairs in proton-proton collisions at sqrt{s} = 13 TeV are measured as a function of kinematic variables of the top quarks and the top quark-antiquark (ttbar) system. In addition, kinematic variables and multiplicities of jets associated with the ttbar production are measured. This analysis is based on data collected by the CMS experiment at the LHC in 2016 corresponding to an integrated luminosity of 35.8/fb. The measurements are performed in the lepton+jets decay channels with a single muon or electron and jets in the final state. The differential cross sections are presented at the particle level, within a phase space close to the experimental acceptance, and at the parton level in the full phase space. The results are compared to several standard model predictions that use different methods and approximations. The kinematic variables of the top quarks and the ttbar system are reasonably described in general, though none predict all the measured distributions. In particular, the transverse momentum distribution of the top quarks is more steeply falling than predicted. The kinematic distributions and multiplicities of jets are adequately modeled by certain combinations of next-to-leading-order calculations and parton shower models.

在质心系能量√s=13 TeV的质子-质子碰撞中，针对顶夸克对（top quark pairs）的产生过程，测量了依赖于顶夸克及顶夸克-反夸克（ttbar）系统运动学变量的微分截面与双微分截面。此外，本研究还测量了与ttbar产生过程相关的喷注（jets）的运动学变量及多重数。本分析基于大型强子对撞机（Large Hadron Collider，LHC）上的CMS实验（Compact Muon Solenoid，CMS）在2016年采集的数据，对应积分亮度为35.8 fb⁻¹。测量在单轻子+喷注衰变道中开展，末态包含单个μ子或电子以及若干喷注。本次测量给出的微分截面分别处于两个层次：一是接近实验接收度的粒子层次相空间，二是全相空间的部分子（parton）层次。研究将上述测量结果与若干采用不同方法和近似方案的标准模型预言进行了对比。总体而言，现有理论预言能够较为合理地复现顶夸克及ttbar系统的运动学变量分布，但没有任何一个预言能够匹配所有的测量分布。具体而言，顶夸克的横动量分布的下降趋势比理论预言更为陡峭。部分喷注的运动学分布及多重数，可以通过若干次领头阶（next-to-leading order，NLO）计算与部分子簇射（parton shower）模型的组合得到较好的描述。