论文标题
在13个TEV PP碰撞事件中使用有效的现场理论搜索新物理学，其中包含顶级夸克对和增强的Z或Higgs Boson
Search for new physics using effective field theory in 13 TeV pp collision events that contain a top quark pair and a boosted Z or Higgs boson
论文作者
论文摘要
包含顶级夸克对的数据样本（$ \ mathrm {t \ bar {t}} $与Lorentz增强的Z或Higgs Boson结合的数据样本用于使用有效的现场理论来搜索新物理学的迹象。该数据对应于138 fb $^{ - 1} $的集成光度，该质子质子碰撞在LHC的13 tev中心能量中产生，并由CMS实验收集。选定的事件包含一个单一的Lepton和Hadronic喷气机，其中包括两种质夸克的衰变，再加上一个额外的大型拉迪乌斯射流，具有高横向动量为Z或Higgs玻色子腐烂，将其变成底部的夸克对。使用机器学习技术来区分$ \ mathrm {t \ bar {t}} $ z或$ \ mathrm {t \ bar {t}} $ h事件和背景过程中的事件，这些事件和事件由$ \ mathrm {t \ bar {t}} $ + jets Production主导。没有观察到新物理学的迹象。测量了增强$ \ mathrm {t \ bar {t}} $ z和$ \ mathrm {t \ bar {t}} $ h的生产的信号强度，并将上限放在$ \ mathrm {t \ bar {t}}} $ z和$ z $ z和$ z和bar}的上限上Z或Higgs玻色子横向动量。使用标准模型被认为是高能量尺度理论的低能有效场理论的框架探测新物理学的效果。将八个可能的六个尺寸运算符添加到标准模型Lagrangian中，其相应系数通过数据限制。
A data sample containing top quark pairs ($\mathrm{t\bar{t}}$) produced in association with a Lorentz-boosted Z or Higgs boson is used to search for signs of new physics using effective field theory. The data correspond to an integrated luminosity of 138 fb$^{-1}$ of proton-proton collisions produced at a center-of-mass energy of 13 TeV at the LHC and collected by the CMS experiment. Selected events contain a single lepton and hadronic jets, including two identified with the decay of bottom quarks, plus an additional large-radius jet with high transverse momentum identified as a Z or Higgs boson decaying to a bottom quark pair. Machine learning techniques are employed to discriminate between $\mathrm{t\bar{t}}$Z or $\mathrm{t\bar{t}}$H events and events from background processes, which are dominated by $\mathrm{t\bar{t}}$ + jets production. No indications of new physics are observed. The signal strengths of boosted $\mathrm{t\bar{t}}$Z and $\mathrm{t\bar{t}}$H production are measured, and upper limits are placed on the $\mathrm{t\bar{t}}$Z and $\mathrm{t\bar{t}}$H differential cross sections as functions of the Z or Higgs boson transverse momentum. The effects of new physics are probed using a framework in which the standard model is considered to be the low-energy effective field theory of a higher energy scale theory. Eight possible dimension-six operators are added to the standard model Lagrangian and their corresponding coefficients are constrained via fits to the data.
