arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2008.07860hep-ex
收藏

在PDMATHAAB 13 TeV上用大横动量顶夸克测量pp碰撞中的微分$\mathrm{t\bar{t}}$产生截面

Measurement of differential $\mathrm{t\bar{t}}$ production cross sections using top quarks at large transverse momenta in pp collisions at $\sqrt{s} =$ 13 TeV

CMS Collaboration

摘要:

报道了在大横动量下产生顶夸克的微分顶夸克对($\mathrm{t\bar{t}}$)产生截面的测量结果。在大型强子对撞机上用CMS探测器收集的数据来自于质心能量为13 TeV的pp碰撞,对应于35.9 fb $^{-1}$的积分亮度。测量使用的事件中,至少有一个顶夸克衰变为t $\to$ Wb $\to$ qq 'b,并重建为一个大半径喷流的横向动量超过400 GeV。第二个顶夸克需要以类似的方式衰变,或者以轻子的方式衰变,这是从重建的电子或μ子、底夸克喷流以及由于未检测到的中微子而丢失的横动量推断出来的。的横截面提取作为一个函数的运动学变量的个人顶夸克或$\mathrm{t\bar{t}}$系统。结果是在粒子水平,在一个区域内的相空间接近的实验接受,并在部分子水平,并进行比较,各种理论模型。在这两个衰变通道中,观测到的绝对截面明显低于理论预测,而归一化的微分测量得到了很好的描述。

英文摘要:

A measurement is reported of differential top quark pair ($\mathrm{t\bar{t}}$) production cross sections, where top quarks are produced at large transverse momenta. The data collected with the CMS detector at the LHC are from pp collisions at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The measurement uses events where at least one top quark decays as t $\to$ Wb $\to$ qq'b and is reconstructed as a large-radius jet with transverse momentum in excess of 400 GeV. The second top quark is required to decay either in a similar way, or leptonically, as inferred from a reconstructed electron or muon, a bottom quark jet, and a missing transverse momentum due to the undetected neutrino. The cross section is extracted as a function of kinematic variables of individual top quarks or of the $\mathrm{t\bar{t}}$ system. The results are presented at the particle level, within a region of phase space close to that of the experimental acceptance, and at the parton level, and are compared to various theoretical models. In both decay channels the observed absolute cross sections are significantly lower than the predictions from theory, while the normalized differential measurements are well described.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑