Understanding electroweak symmetry breaking from LHC data

了解大型强子对撞机数据中的电弱对称性破缺

• 批准号: 386346-2013
• 负责人: Grégoire, Thomas
• 金额: $ 4.37万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=617864
• 关键词: Understanding; electroweak; symmetry; breaking; LHC

The Standard Model(SM) of particle physics gives a description of all the particles and forces known to date. Over the past 50 years it has been tested to exquisite precision. The theoretical description of the Standard Model is based on an elegant symmetry principle. It allows to describe of all interactions in term of only three parameters, namely the gauge coupling constants. However, the same principle predicts that all the particles of the SM should be massless. This is not the case, which means that the symmetry must somehow be broken. This phenomenon is called electroweak symmetry breaking(EWSB) and the physics responsible for it remains to a large extend unknown and uncovering it has been one of the main quests of high energy physics, both theoretical and experimental for the past two or three decades. The Large Hadron Collider now in operation in CERN near Geneva Switzerland has been built with this objective in mind. It is a circular accelerator with a circumference of 27km that collides two beams of protons with very high energy (each beam has now an energy of 4 TeV). Two detectors that record the complicated results of the collisions have recently discovered what seem to be the Higgs boson and the announcement of this discovery was made public in June of 2012, creating a lot of excitement, for particle physicists in particular, but for the general public as well. While the Higgs field offers a good description of EWSB, the quest to fully understand it is far from over. For example, the SM with a single Higgs boson requires a very precise fine-tuning of parameters. It also, among other things, doesn't give an explanation for the observation of dark matter, or explain the structure of the different masses and mixing of the SM particles.My research program tries to understand some of these issues by proposing alternatives theories of EWSB. For example, I am studying supersymmetric models and Little Higgs models. Those theories predict new particles and/or forces that could be seen at LHC. In various research projects I propose to build new models that offer solutions to the shortcomings of the SM, and study their consequences for what the LHC might observe.

粒子物理的标准模型（SM）给出了迄今已知的所有颗粒和力的描述。在过去的50年中，已将其测试为精确的精度。标准模型的理论描述基于优雅的对称原理。它允许仅以三个参数（即量规耦合常数）描述所有相互作用。但是，相同的原理预测SM的所有粒子都应无质量。事实并非如此，这意味着对称性必须以某种方式被打破。这种现象称为Electroweak对称性破坏（EWSB），并且负责它的物理学仍然是一个很大的延伸未知，并且发现它一直是高能物理学的主要问题之一，在过去的两到三十年中，理论和实验性都是如此。现在，在瑞士日内瓦附近的CERN运营的大型强子对撞机已经在这一目标中构建。它是一个圆周加速器，周长为27公里，它碰撞了两个具有很高能量的质子的光束（现在每个梁的能量为4 TEV）。两名记录碰撞结果复杂结果的探测器最近发现了似乎是希格斯玻色子的东西，并且这一发现的宣布在2012年6月公开了，特别是对于粒子物理学家而言，这引起了很多兴奋，但对于普通大众来说也是如此。尽管Higgs领域很好地描述了EWSB，但要完全理解它远远没有结束。例如，具有单个希格斯玻色子的SM需要非常精确的参数微调。除其他外，它也没有为观察暗物质的观察提供解释，也不能解释不同质量的结构和SM颗粒的混合。我的研究计划试图通过提出EWSB的替代理论来理解其中一些问题。例如，我正在研究超对称模型和小希格斯模型。这些理论可以预测在LHC上可以看到的新粒子和/或力。在各种研究项目中，我建议建立新的模型，为SM的缺点提供解决方案，并研究其对LHC可能观察到的后果。