Search for flavor-changing neutral currents in top quark decays t ? H c and t ? H u in multilepton final states in proton-proton collisions at s = 13 TeV with the ATLAS detector
Search for flavor-changing neutral currents in top quark decays t ? H c and t ? H u in multilepton final states in proton-proton collisions at s = 13 TeV with the ATLAS detector
复制标题
寻找顶夸克衰变中改变风味的中性流 t ？
DOI：
10.1103/physrevd.98.032002
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发表时间：
2018
影响因子：
5
通讯作者：
Aaboud M
中科院分区：
文献类型：
--
作者：
Aaboud M
在标准模型中，味道变化的中性流在树的水平上并不存在，并且在循环过程中被Cabibbo-Kobayashi-Maskawa矩阵的么正性所抑制;顶夸克衰变过程的相应速率在实验上是不可观测的。标准模型的扩展可以产生新的改变味道的中性电流过程，从而产生信号，如果观察到这些信号，将成为新相互作用的明确证据。利用大型强子对撞机上的ATLAS探测器记录的对应于质心能量下的碰撞的积分光度的数据集来搜索顶夸克，该顶夸克随着希格斯玻色子的发射而衰变到上夸克或魅夸克，随后希格斯玻色子衰变到具有至少一个电子或μ子的终态。未观察到信号，并获得了95%置信水平下的分支分数和限度（两种情况下的预期限度均为0.15%）。
Flavor-changing neutral currents are not present in the Standard Model at tree level and are suppressed in loop processes by the unitarity of the Cabibbo-Kobayashi-Maskawa matrix; the corresponding rates for top quark decay processes are experimentally unobservable. Extensions of the Standard Model can generate new flavor-changing neutral current processes, leading to signals which, if observed, would be unambiguous evidence of new interactions. A data set corresponding to an integrated luminosity ofofcollisions at a center-of-mass energy ofrecorded with the ATLAS detector at the Large Hadron Collider is used to search for top quarks decaying to up or charm quarks with the emission of a Higgs boson, with subsequent Higgs boson decay to final states with at least one electron or muon. No signal is observed and limits on the branching fractionsandat 95% confidence level are obtained (with expected limits of 0.15% in both cases).