arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1001.4577hep-ex
收藏

在缺失横向能量加喷流拓扑中寻找sqrt{s}=1.96 TeV的pbar p碰撞中的单顶夸克产生

Search for single top quark production in pbar p collisions at sqrt{s}=1.96 TeV in the missing transverse energy plus jets topology

CDF Collaboration, T. Aaltonen

摘要:

我们报告了一个搜索的单顶夸克生产与CDF II探测器使用2.1 fb-1的积分亮度的pbar p碰撞在sqrt{s}=1.96 TeV。所选择的数据包括以横向平面和强子喷流中的大能量不平衡为特征的事件,并且没有确定的电子和μ子,因此样品富含W -> τ nu衰变。为了抑制背景,通过神经网络施加额外的运动学和拓扑学要求,并且至少一个喷流必须被识别为b夸克喷流。我们测量了过量的信号事件与标准模型预测一致,但与没有单个顶夸克产生的模型不一致,标准差(sigma)为2.1,平均预期灵敏度为1.4 sigma。假设顶夸克的质量为175 GeV/c2,并将过剩归因于单个顶夸克的产生,测量的截面为4.9+2.5-2.2(stat+syst)pb,与独立数据集的测量结果和标准模型的预测一致。

英文摘要:

We report a search for single top quark production with the CDF II detector using 2.1 fb-1 of integrated luminosity of pbar p collisions at sqrt{s}=1.96 TeV. The data selected consist of events characterized by large energy imbalance in the transverse plane and hadronic jets, and no identified electrons and muons, so the sample is enriched in W -> tau nu decays. In order to suppress backgrounds, additional kinematic and topological requirements are imposed through a neural network, and at least one of the jets must be identified as a b-quark jet. We measure an excess of signal-like events in agreement with the standard model prediction, but inconsistent with a model without single top quark production by 2.1 standard deviations (sigma), with a median expected sensitivity of 1.4 sigma. Assuming a top quark mass of 175 GeV/c2 and ascribing the excess to single top quark production, the cross section is measured to be 4.9+2.5-2.2(stat+syst)pb, consistent with measurements performed in independent datasets and with the standard model prediction.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑