Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector
Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector
复制标题
使用 ATLAS 探测器产生希格斯玻色子和顶夸克对的证据
DOI：
10.1103/physrevd.97.072003
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发表时间：
2018-04-09
影响因子：
5
通讯作者：
Zwalinski, L.
中科院分区：
文献类型：
--
作者：
Aaboud, M.;Aad, G.;Zwalinski, L.
本文报道了在barH上寻找Higgs玻色子与顶夸克对（tt（B））的关联产生。搜索是在多轻子末态中进行的，使用的数据集对应于由ATLAS实验在质量中心能量根s = 13 TeV的大型强子对撞机上记录的质子-质子碰撞数据的积分光度为36.1 fb（-1）。希格斯玻色子衰变到WW*、tau tau和ZZ* 是目标。七个最后的状态，分类的数量和味道的带电轻子候选人，检查的标准模型希格斯玻色子的质量为125 GeV和一对顶夸克的存在。超过标准模型过程预期背景的事件过多，观察到的显著性为4.1标准差，而预期为2.8标准差。（tt（B）/barH）产生截面的最佳拟合为sot（tt（B）/barH）= 790（-210）（+230）fb，与标准模型预测的507（-50）（+35）fb一致。该结果与来自ATLAS实验的其他tt（B）在barH上的搜索的组合，该ATLAS实验使用希格斯玻色子衰变模式在bar、gamma和ZZ* -> 4l上到B（B），具有4.2标准偏差的观察到的显著性，相比之下，预期为3.8标准偏差。这为tt（B）over barH产生模式提供了证据。
A search for the associated production of the Higgs boson with a top quark pair (tt (b) over barH) is reported. The search is performed in multilepton final states using a data set corresponding to an integrated luminosity of 36.1 fb(-1) of proton-proton collision data recorded by the ATLAS experiment at a center-of-mass energy root s = 13 TeV at the Large Hadron Collider. Higgs boson decays to WW*, tau tau, and ZZ* are targeted. Seven final states, categorized by the number and flavor of charged-lepton candidates, are examined for the presence of the Standard Model Higgs boson with a mass of 125 GeVand a pair of top quarks. An excess of events over the expected background from Standard Model processes is found with an observed significance of 4.1 standard deviations, compared to an expectation of 2.8 standard deviations. The best fit for the (tt (b) over barH) production cross section is sot (tt (b) over barH) = 790(-210)(+230) fb, in agreement with the Standard Model prediction of 507(-50)(+35) fb. The combination of this result with other tt (b) over barH searches from the ATLAS experiment using the Higgs boson decay modes to b (b) over bar, gamma gamma and ZZ* -> 4l, has an observed significance of 4.2 standard deviations, compared to an expectation of 3.8 standard deviations. This provides evidence for the tt (b) over barH production mode.