质子-质子碰撞中顶夸克对衰变为双轻子与喷注的四顶夸克事例中寻找共振
Search for a resonance in events with four top quarks decaying into two leptons and jets in proton-proton collisions
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中文总结 AI 辅助
在CMS实验采集的13 TeV与13.6 TeV质子-质子碰撞数据中，首次在双轻子道中寻找仅与顶夸克相互作用的新型玻色子对应的四顶夸克共振，未观测到显著超出本底的事例，设定了共振产生截面上限并排除了部分参数空间。
中文摘要 AI 辅助
本文介绍了在包含四个顶夸克的事例中寻找重共振的研究，并在仅与顶夸克相互作用的新型矢量、标量或赝标量玻色子模型中对结果进行了解释。分析了欧洲核子研究中心大型强子对撞机（CERN LHC）的CMS实验在质心系能量13 TeV和13.6 TeV下采集的质子-质子碰撞数据，对应的积分亮度分别为138 fb⁻¹和35 fb⁻¹。筛选出包含两个轻子（电子或缪子）和喷注的事例，通过可变半径喷注聚类算法形成的一对喷注重建重共振的质量，采用机器学习方法识别这些喷注是否来自完全强子衰变的顶夸克，根据双喷注不变质量从数据中估计误识别喷注的主要本底。数据中未观测到显著超出本底的事例，在95%置信水平下，针对质量范围500 GeV至4 TeV、相对宽度4%至50%的共振设定了共振产生截面的上限；在矢量中介基准模型中，相对宽度50%的共振被排除至质量850 GeV，预期排除限为1000 GeV，这是在双轻子道中对这些模型开展的首次专门寻找。
英文摘要
A search for a heavy resonance in events containing four top quarks is presented and interpreted in models featuring a new vector, scalar, or pseudoscalar boson that interacts exclusively with top quarks. Proton-proton collision data collected by the CMS experiment at the CERN LHC at centre-of-mass energies of 13 and 13.6 TeV are analysed, corresponding to integrated luminosities of 138 and 35 fb$^{-1}$, respectively. Events with two leptons (electrons or muons) and jets are selected. The mass of the heavy resonance is reconstructed from a pair of jets that are formed using a variable-radius jet clustering algorithm. A machine-learning approach is used to identify whether these jets originate from top quarks that decay fully hadronically. The dominant background from misidentified jets is estimated from data as a function of the dijet invariant mass. No significant excess is observed in data. Upper limits at 95% confidence level are set on the resonance production cross section for resonance masses between 500 GeV and 4 TeV, and relative widths ranging from 4 to 50%. In the vector-mediator benchmark, resonances with 50% relative width are excluded up to masses of 850 GeV, with an expected exclusion limit of 1000 GeV. This is the first dedicated search for these models in the two lepton channel.
