Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector
Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector
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DOI：
10.1016/j.physletb.2015.07.079
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发表时间：
2015-06
期刊：
影响因子：
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通讯作者：
Atlas Collaboration
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文献类型：
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作者：
Atlas Collaboration
在多轻子末态中，我们使用ATLAS实验在s= 8 TeV时记录的20.3 fb− 1质子-质子碰撞数据，对希格斯玻色子与顶夸克对的相关产生进行了研究。针对衰变H→ W W、ττ和Z Z的五个末态，我们考察了标准模型希格斯玻色子的存在：两个没有强子衰变τ轻子的同电荷轻轻子（e或μ）;三个轻轻子;两个有强子衰变τ轻子的同电荷轻轻子;四个轻轻子;一个轻轻子和两个强子衰变τ轻子。未观察到显著超出背景预期的事件。假设希格斯玻色子的质量为125 GeV，t t ′ H产生截面的最佳拟合值是SM期望值的2.1− 1.2+ 1.4倍，在95%置信水平下观测到的（期望）上限是SM速率的4.7（2.4）倍。与仅背景假设相容性的p值为1.8σ;存在标准模型信号时的期望值为0.9σ。
A search for the associated production of the Higgs boson with a top quark pair is performed in multilepton final states using 20.3 fb− 1 of proton–proton collision data recorded by the ATLAS experiment at s= 8 TeV at the Large Hadron Collider. Five final states, targeting the decays H→ W W⁎, ττ, and Z Z⁎, are examined for the presence of the Standard Model (SM) Higgs boson: two same-charge light leptons (e or μ) without a hadronically decaying τ lepton; three light leptons; two same-charge light leptons with a hadronically decaying τ lepton; four light leptons; and one light lepton and two hadronically decaying τ leptons. No significant excess of events is observed above the background expectation. The best fit for the t t¯ H production cross section, assuming a Higgs boson mass of 125 GeV, is 2.1− 1.2+ 1.4 times the SM expectation, and the observed (expected) upper limit at the 95% confidence level is 4.7 (2.4) times the SM rate. The p-value for compatibility with the background-only hypothesis is 1.8σ; the expectation in the presence of a Standard Model signal is 0.9σ.