Search for vectorlike B quarks in events with one isolated lepton, missing transverse momentum, and jets at s = 8 TeV with the ATLAS detector
Search for vectorlike B quarks in events with one isolated lepton, missing transverse momentum, and jets at s = 8 TeV with the ATLAS detector
复制标题
使用 ATLAS 探测器在具有一个孤立轻子、缺失横向动量和 s = 8 TeV 喷流的事件中搜索矢量 B 夸克
DOI：
10.1103/physrevd.91.112011
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发表时间：
2015
影响因子：
5
通讯作者：
Aad G
中科院分区：
文献类型：
--
作者：
Aad G
本文研究了重类矢量下型夸克对的产生。分析探讨了轻子加喷流的最终状态，其特征在于事件与一个孤立的带电轻子（电子或μ子），显着失踪的横向动量，和多个喷流。一个或多个喷注必须被标记为来自夸克，至少一对喷注必须被标记为来自电弱玻色子的强子衰变。该分析使用了2012年由ATLAS探测器在LHC记录的碰撞的完整数据样本，其质心能量为8 TeV，对应于积分光度为。未观察到显著超出预期背景的事件。限制设置在矢量样的生产，作为分支比的函数，假设允许的衰变模式。在衰减分支比为100%的手性极限下，观察到（预期）95%CL类矢量质量的下限是810 GeV（760 GeV）。当类矢量夸克的分支比与单重态的分支比相当时，观测到的（预期的）95% C.类矢量质量的下限为640 GeV（505 GeV）。同样的分析，当用来研究一个有色的，电荷奇异的费米子的对产生，随后的衰变，设置一个观察到的（预期的）95% C. L。840 GeV（780 GeV）的质量下限。
A search has been performed for pair production of heavy vectorlike down-type () quarks. The analysis explores the lepton-plus-jets final state, characterized by events with one isolated charged lepton (electron or muon), significant missing transverse momentum, and multiple jets. One or more jets are required to be tagged as arising fromquarks, and at least one pair of jets must be tagged as arising from the hadronic decay of an electroweak boson. The analysis uses the full data sample ofcollisions recorded in 2012 by the ATLAS detector at the LHC, operating at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of. No significant excess of events is observed above the expected background. Limits are set on vectorlikeproduction, as a function of thebranching ratios, assuming the allowable decay modes are. In the chiral limit with a branching ratio of 100% for the decay, the observed (expected) 95% C.L. lower limit on the vectorlikemass is 810 GeV (760 GeV). In the case where the vectorlikequark has branching ratio values corresponding to those of ansinglet state, the observed (expected) 95% C.L. lower limit on the vectorlikemass is 640 GeV (505 GeV). The same analysis, when used to investigate pair production of a colored, chargeexotic fermion, with subsequent decay, sets an observed (expected) 95% C.L. lower limit on themass of 840 GeV (780 GeV).