High Energy Physics Research at LHC with the CMS Experiment

20 世纪的主要智力成就之一是粒子物理学标准模型 (SM) 的发展。该模型成功地将当时已知的所有基本粒子分类为具有相似量子特性的群的层次结构。最近，欧洲核子研究中心大型强子对撞机发现的希格斯玻色子证实了该模型迄今为止的有效性。然而，目前存在的标准模型留下了许多关于宇宙的问题，包括诸如希格斯质量为何具有其价值的基本问题。大型强子对撞机 (LHC) 是首屈一指的能源前沿粒子加速器，在瑞士日内瓦附近的 CERN 实验室运行。 它是目前回答这些超越标准模型问题和研究希格斯玻色子特性的最重要的设施之一。大型强子对撞机的紧凑型介子螺线管 (CMS) 实验的主要功能之一是发现标准模型之外的新物理现象。这里提出的工作将分析 CMS 实验的数据，寻找超越标准模型 (BSM) 物理的信号。该奖项将资助 CMS 实验的两个方面：1）进一步搜索 BSM 物理；2）帮助构建 CMS 第一阶段前向像素探测器（FPix）升级，这将增强 CMS 发现 BSM 物理的能力。 BSM 的一些理论预测包括几种不同的希格斯玻色子，它们与 b 夸克的耦合增强。该奖项将允许使用多元回归技术改进 b 夸克研究，以更好地估计 b 喷流能量规模，从而提高希格斯玻色子质量分辨率。这种所谓的射流子结构技术对于 CMS 得出的所有物理结果都很重要，因为许多衰变通道需要改进的射流能量校正。 该奖项提供的另一个 BSM 搜索是搜索预测会衰变为 ttbar 夸克对的重矢量玻色子（通常称为 Z 素数）。 ttbar 衰减的最终状态是 b 型喷气机，再次受益于该奖项中的喷气机能量校正工作。该奖项还提供了 FPix 升级的重要部分，这些部分正在 FermiLab 进行测试。 CMS 前向像素升级将允许精确的顶点位置，这是所有物理研究所需的，即使是在不久的将来大型强子对撞机运行中预期的恶劣环境（非常高的亮度）中也是如此。 CMS 前向像素探测器采用最先进的硅技术进行粒子探测，并结合同样先进的读出电子设备。电流检测器采用了抗辐射硬技术和凸点接合的创新技术，以应对高辐射环境下的房地产挑战。这些技术将大大延长外层空间研究中使用的探测器的使用寿命，并改进医疗应用的生物传感微型设备。

One of the major intellectual achievements of the 20th century was the development of the Standard Model (SM) of particle physics. This model succeeded in classifying all of the elementary particles known at the time into a hierarchy of groups having similar quantum properties. The validity of this model to date was recently confirmed by the discovery of the Higgs boson at the Large Hadron Collider at CERN. However, the Standard Model as it currently exists leaves open many questions about the universe, including such fundamental questions as to why the Higgs mass has the value it has. The Large Hadron Collider (LHC) is the premier Energy Frontier particle accelerator operating at the CERN laboratory near Geneva Switzerland. It is currently one of the foremost facilities for answering these Beyond the Standard Model questions and studying the properties of the Higgs boson. One of the primary functions of the Compact Muon Solenoid (CMS) experiment at the LHC is to discover new physics beyond the Standard Model. The work proposed here will analyze data from the CMS experiment looking for signals of Beyond the Standard Model (BSM) physics. This award will fund two aspects of the CMS experiment: 1) further searches for BSM physics and 2) help build the CMS Phase I forward pixel detector (FPix) upgrade, which will enhance the ability of CMS to discover BSM physics. Some of the BSM theoretical predictions include several different Higgs boson that have enhanced coupling to b-quarks. This award will allow an improved b-quark study using a multivariate regression technique to better estimate the b-jet energy scale and thereby improve on the Higgs boson mass resolution. This so-called jet substructure technique is important for all the physics results coming out of CMS, as many decay channels require improved jet energy corrections. Another BSM search that this award provides is the search for a heavy vector boson (generally referred to as Z prime) predicted to decay to a ttbar pair of quarks. The final state of this ttbar decay is b-jets, again, benefiting from the jet energy correction work in this award. The award also provides important parts of the FPix upgrade which are being tested at FermiLab. The CMS Forward pixel upgrade will allow the precise vertex location, needed for all physics studies, even in the harsh environment (very high luminosity) expected in near future LHC running. The CMS Forward Pixel Detector uses state-of-the art silicon technology for particle detection combined with equally sophisticated readout electronics. Innovative techniques of radiation hard technology and bump bonding have been used in the current detector to meet the real estate challenges in a high radiation environment. These techniques would greatly enhance the life span of detectors used in outer space research and improve bio-sensing miniature devices for medical applications.