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arXiv 0901.3367hep-ph
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在LHC上识别来自Gluino衰变的多顶事件

Identifying Multi-Top Events from Gluino Decay at the LHC

Bobby S. Acharya, Phill Grajek, Gordon L. Kane, Eric Kuflik, Kerim Suruliz, Lian-Tao Wang

摘要:

我们研究的LHC信号的光胶子的级联衰变是占主导地位的通道,涉及顶,有时,底夸克。这是最近考虑的一些超对称破缺场景的通用签名,其中squarks比gauginos重。第三代末态通常占主导地位,因为第三代方在这些模型中通常稍微轻一些。在大型强子对撞机上,我们证明了早期发现是可能的,这是由于多轻子多底末态的存在,这些末态具有相当低的标准模型背景。我们发现最好的发现通道是同号双轻子。进入tt、tb和bb态的相对衰变分支比携带了关于基础模型的重要信息。虽然重建将产生顶夸克存在的事件的证据,我们证明,识别多个顶夸克遭受低效率和大的组合背景,由于大量的末态粒子。我们提出了一种拟合方法,它利用了大量的渠道过剩。我们证明这样的方法将使我们能够提取信息的衰变分支比与中等积分亮度。此外,该方法还给出了胶子产生截面的上界和胶子质量的估计。

英文摘要:

We study the LHC signal of a light gluino whose cascade decay is dominated by channels involving top, and, sometimes, bottom quarks. This is a generic signature for a number of supersymmetry breaking scenarios considered recently, where the squarks are heavier than gauginos. Third generation final states generically dominate since third generation squarks are typically somewhat lighter in these models. At the LHC we demonstrate that early discovery is possible due to the existence of multi-lepton multi-bottom final states which have fairly low Standard Model background. We find that the best discovery channel is 'same sign dilepton'. The relative decay branching ratios into tt, tb and bb states carry important information about the underlying model. Although reconstruction will yield evidence for the existence of top quarks in the event, we demonstrate that identifying multiple top quarks suffers from low efficiency and large combinatorial background, due to the large number of final state particles. We propose a fitting method which takes advantage of excesses in a large number of channels. We demonstrate such a method will allow us to extract information about decay branching ratios with moderate integrated luminosities. In addition, the method also gives an upper bound on the gluino production cross section and an estimate of the gluino mass.

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。

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