Analysis of events with b-jets and a pair of leptons of the same charge in pp collisions at s = 8 $$ \sqrt{s}=8 $$ TeV with the ATLAS detector
Analysis of events with b-jets and a pair of leptons of the same charge in pp collisions at s = 8 $$ \sqrt{s}=8 $$ TeV with the ATLAS detector
复制标题
使用 ATLAS 探测器分析 s = 8 $$ sqrt{s}=8 $$ TeV 时 pp 碰撞中 b 喷流和一对相同电荷轻子的事件
DOI：
10.1007/jhep10(2015)150
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发表时间：
2015
影响因子：
5.4
通讯作者：
Aad G
中科院分区：
文献类型：
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作者：
Aad G
分析了包含喷流的事件，其中包括至少一个带b标记的喷流、相当大的横向动量缺失，以及至少两个轻子(包括一对相同的电荷)，其中喷流和轻子横向动量的标量和很大。使用的是由大型强子对撞机的ATLAS探测器记录的pp碰撞atTeV的积分光度为20.3fb−1的数据样本。标准模型过程很少产生这些终态，但除了标准模型之外，还有几个物理模型预测了此类事件的增强产生速度；这里讨论的模型包括类矢量夸克的产生，增强的四顶夸克产生，手征b‘夸克的成对产生，以及两个带正电的顶夸克的产生。定义了11个信号区域；当搜索每类模型时，组合这些区域的子集。在对带正电的顶夸克对产生主要敏感的三个信号区，数据产额与背景预期一致。在为寻找矢量型夸克和手征b‘夸克而定义的八个信号区中，来自背景的数据事件比预期的要多，但差异的重要性小于两个标准差。在为搜索四顶夸克产生而定义的五个信号区中，偏差达到2.5标准差。结果被用来设定各种型号的95%化学发光限值。
An analysis is presented of events containing jets including at least one b-tagged jet, sizeable missing transverse momentum, and at least two leptons including a pair of the same electric charge, with the scalar sum of the jet and lepton transverse momenta being large. A data sample with an integrated luminosity of 20.3 fb− 1 of pp collisions atTeV recorded by the ATLAS detector at the Large Hadron Collider is used. Standard Model processes rarely produce these final states, but there are several models of physics beyond the Standard Model that predict an enhanced rate of production of such events; the ones considered here are production of vector-like quarks, enhanced four-top-quark production, pair production of chiral b′-quarks, and production of two positively charged top quarks. Eleven signal regions are defined; subsets of these regions are combined when searching for each class of models. In the three signal regions primarily sensitive to positively charged top quark pair production, the data yield is consistent with the background expectation. There are more data events than expected from background in the set of eight signal regions defined for searching for vector-like quarks and chiral b′-quarks, but the significance of the discrepancy is less than two standard deviations. The discrepancy reaches 2.5 standard deviations in the set of five signal regions defined for searching for four-top-quark production. The results are used to set 95% CL limits on various models.