"Table 186" 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.

本研究测量了质心系能量√s=13 TeV的质子-质子碰撞中顶夸克对（top quark pair）产生的微分截面（differential cross section）与双微分截面（double-differential cross section），测量结果作为顶夸克以及顶夸克-反顶夸克（ttbar）系统的运动学变量的函数给出；此外，本研究还测量了与ttbar产生过程相关的喷注（jet）的运动学变量与多重数。本分析基于大型强子对撞机（Large Hadron Collider, LHC）上的CMS实验在2016年采集的数据，对应的积分亮度（integrated luminosity）为35.8 fb⁻¹。测量在末态包含单个μ子或电子以及喷注的轻子+喷注衰变道（lepton+jets decay channels）中完成。微分截面分别在接近实验接收度（experimental acceptance）的相空间内的粒子级（particle level），以及全相空间内的部分子级（parton level）上给出。将测量结果与若干采用不同方法与近似方案的标准模型（Standard Model）预言进行了对比。总体而言，顶夸克与ttbar系统的运动学变量得到了较为合理的描述，但没有任何一个理论预言能够复现所有的测量分布，具体而言，顶夸克的横向动量（transverse momentum）分布的下降斜率比理论预言更为陡峭。部分喷注的运动学分布与多重数能够通过次领头阶（next-to-leading-order, NLO）计算与部分子簇射（parton shower）模型的若干组合得到较好的描述。