Search for top squarks in final states with one isolated lepton, jets, and missing transverse momentum in √s=13 TeV pp collisions with the ATLAS detector
Search for top squarks in final states with one isolated lepton, jets, and missing transverse momentum in √s=13 TeV pp collisions with the ATLAS detector
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DOI：
10.1103/physrevd.94.052009
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发表时间：
2016-09-19
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.
报告了对顶夸克（顶夸克的超对称伴侣）的搜索结果，该顶夸克处于具有一个孤立电子或μ子、喷流和缺失横向动量的最终状态。该搜索使用了 ATLAS 探测器记录的 2015 年 LHC pp 碰撞数据，质心能量根 s = 13 TeV，对应的积分光度为 3.2 fb(-1)。该分析针对两种类型的信号模型：谷子介导的顶夸克配对产生（具有几乎质量简并的顶夸克和中性子）以及顶夸克的直接配对产生（衰变到顶夸克和最轻的中性子）。两种信号场景中的实验特征类似于与大量缺失横向动量相关的顶夸克对的特征。没有观察到超过标准模型背景预测的显着超出，并且对谷子和顶夸克质量的排除限制设置为 95% 的置信水平。结果将 LHC run-1 对高谷子质量和低顶夸克质量区域中谷子质量的排除限制扩展到 1460 GeV，并为具有无质量最轻中子的直接顶夸克模型添加了从 745 到 780 GeV 的排除顶夸克质量区域。结果也被重新解释，以在矢量顶夸克模型中设置排除限制。
The results of a search for the top squark, the supersymmetric partner of the top quark, in final states with one isolated electron or muon, jets, and missing transverse momentum are reported. The search uses the 2015 LHC pp collision data at a center-of-mass energy of root s = 13 TeV recorded by the ATLAS detector and corresponding to an integrated luminosity of 3.2 fb(-1). The analysis targets two types of signal models: gluino-mediated pair production of top squarks with a nearly mass-degenerate top squark and neutralino and direct pair production of top squarks, decaying to the top quark and the lightest neutralino. The experimental signature in both signal scenarios is similar to that of a top quark pair produced in association with large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits on gluino and top squark masses are set at 95% confidence level. The results extend the LHC run-1 exclusion limit on the gluino mass up to 1460 GeV in the gluino-mediated scenario in the high gluino and low top squark mass region and add an excluded top squark mass region from 745 to 780 GeV for the direct top squark model with a massless lightest neutralino. The results are also reinterpreted to set exclusion limits in a model of vectorlike top quarks.