Search for BSM phenomena is one of the fundamental goals of the LHC experiments. Many BSM models foresee long-lived particles which decay far from the production vertex and a big effort has been done both by the ATLAS and CMS collaborations to detect these long-lived particles. A specific, widely studied, example for such searches is made through the measurement of displaced vertices produced by a narrow resonance decaying to a muon pair. This paper will first analyze what has been done so far and will try to evaluate if there are improvements which may allow enhancing the discovery potential at LHC for such particles. The outcome of this work is that while long-lived particles decaying more than 1 cm from the primary vertex have been carefully studied by ATLAS and CMS, the region within a few millimeters from the primary vertex may have been partially neglected. A new approach for searching such resonances, fully based on data, will then be proposed which allows minimizing systematic uncertainties while keeping at a maximum the discovery potentiality for long-lived neutral resonances which decay a few millimeters from the primary vertex.

中文翻译：

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一种使用 ATLAS 和 CMS 在短距离区域搜索 dimuon 位移顶点的替代方法


寻找 BSM 现象是 LHC 实验的基本目标之一。许多 BSM 模型预见到长寿命颗粒会在远离生产顶点的地方衰变，因此 ATLAS 和 CMS 合作已经付出了巨大努力来检测这些长寿命颗粒。这种搜索的一个具体的、被广泛研究的例子是通过测量由衰减到 μ 子对的窄共振产生的位移顶点来制作的。本文将首先分析迄今为止所做的工作，并尝试评估是否有改进可以提高 LHC 对此类粒子的发现潜力。这项工作的结果是，虽然 ATLAS 和 CMS 已经仔细研究了从主顶点衰减超过 1 厘米的长寿命粒子，但距离主顶点几毫米以内的区域可能被部分忽略了。然后，将提出一种完全基于数据搜索此类共振的新方法，该方法可以最大限度地减少系统不确定性，同时最大限度地保持从主顶点衰减几毫米的长寿命中性共振的发现潜力。