"Table 15" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ collisions at $\sqrt{s}=13\,$ TeV using the ATLAS detector"

Measurements are made of differential cross-sections of highly boosted pair-produced top quarks as a function of top-quark and $t\bar{t}$ system kinematic observables using proton--proton collisions at a center-of-mass energy of $\sqrt{s} = 13$ TeV. The data set corresponds to an integrated luminosity of $36.1$ fb$^{-1}$, recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Events with two large-radius jets in the final state, one with transverse momentum $p_{\rm T} > 500$ GeV and a second with $p_{\rm T} > 350$ GeV, are used for the measurement. The top-quark candidates are separated from the multijet background using jet substructure information and association with a $b$-tagged jet. The measured spectra are corrected for detector effects to a particle-level fiducial phase space and a parton-level limited phase space, and are compared to several Monte Carlo simulations by means of calculated $\chi^2$ values. The cross-section for $t\bar{t}$ production in the fiducial phase-space region is $292 \pm 7 \rm{(stat)} \pm 76 \rm{(syst)}$ fb, to be compared to the theoretical prediction of $384 \pm 36$ fb.

本研究利用欧洲核子研究中心（CERN）大型强子对撞机（Large Hadron Collider, LHC）上的ATLAS探测器（ATLAS）在2015至2016年采集的、积分亮度为36.1 fb⁻¹的质心能量√s=13 TeV质子-质子碰撞样本，测量了高洛伦兹增强的成对产生顶夸克（top quark）的微分截面，测量结果以顶夸克及顶夸克-反顶夸克对（$tar{t}$）系统的运动学可观测量为函数形式展开。本次测量选取末态包含两个大半径喷注（large-radius jet）的事例：其中一个喷注的横向动量（transverse momentum, $p_{
m T}$）大于500 GeV，另一个喷注的横向动量大于350 GeV。研究团队通过喷注子结构信息，以及与被b标记（b-tagged）喷注的关联，将顶夸克候选事例从多喷注本底中分离出来。针对探测器效应，我们将测量得到的能谱校正至粒子级 fiducial 相空间（fiducial phase space）以及部分子级受限相空间，并通过计算$chi^2$值与多款蒙特卡洛（Monte Carlo）模拟结果进行对比。在fiducial相空间区域内，顶夸克-反顶夸克对产生的截面为$292 pm 7
m{(统计)} pm 76
m{(系统)}$ fb，该结果可与理论预言的$384 pm 36$ fb进行对比。