论文标题
在与Atlas检测器的PP碰撞中，搜索成对生产的类似矢量的顶部和底部合作伙伴
Search for pair-produced vector-like top and bottom partners in events with large missing transverse momentum in pp collisions with the ATLAS detector
论文作者
论文摘要
使用一个精确的Lepton（$ e $或$μ$），至少有四个喷气式飞机，包括至少一个$ b $ tage的喷气式喷气式飞机，并提出了大量的横向动量。分析来自Proton-Proton碰撞的质量中心能量$ \ sqrt {s} = 13 $ TEV，由Atlas detector在LHC上从2015年到2018年记录，对应于139 fb $^{ - 1} $的综合亮度。考虑到顶部和底部夸克的类似矢量的合作伙伴$ t $和$ b $，以及带有电荷+5/3的矢量样$ x $，假设其衰减成$ W $，$ z $或Higgs Boson和Higgs Boson和第三代夸克。没有观察到与标准模型期望的显着偏差。 $ t $和$ b $ quark对的生产横截面的上限作为其质量的函数，用于各种衰减分支比例。质量上最强的下限是1.59 TEV，假设质量分级VLQ和分支比对应于弱的dublet模型，而独家$ t \ rightarrow zt $（$ b/x \ rightarrow wt wt $）的独家$ t \ rightarrow zt $（1.46 tev）的1.47 TEV（1.46 TEV）。此外，对于所有可能的分支率，$ t $和$ b $ quark群众的下限是衍生得出的。
A search for pair-produced vector-like quarks using events with exactly one lepton ($e$ or $μ$), at least four jets including at least one $b$-tagged jet, and large missing transverse momentum is presented. Data from proton-proton collisions at a centre-of-mass energy of $\sqrt{s} = 13$ TeV, recorded by the ATLAS detector at the LHC from 2015 to 2018 and corresponding to an integrated luminosity of 139 fb$^{-1}$, are analysed. Vector-like partners $T$ and $B$ of the top and bottom quarks are considered, as is a vector-like $X$ with charge +5/3, assuming their decay into a $W$, $Z$, or Higgs boson and a third-generation quark. No significant deviations from the Standard Model expectation are observed. Upper limits on the production cross-section of $T$ and $B$ quark pairs as a function of their mass are derived for various decay branching ratio scenarios. The strongest lower limits on the masses are 1.59 TeV assuming mass-degenerate VLQs and branching ratios corresponding to the weak-isospin doublet model, and 1.47 TeV (1.46 TeV) for exclusive $T \rightarrow Zt$ ($B/X \rightarrow Wt$) decays. In addition, lower limits on the $T$ and $B$ quark masses are derived for all possible branching ratios.
