Searches for Beyond the Standard Model Physics with Hadronic Topologies

利用强子拓扑寻找超越标准模型物理的研究

• 批准号: ST/N003934/3
• 负责人: Gabriel Facini
• 金额: $ 8.26万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FN003934%2F3
• 关键词: Searches; Beyond; Standard; Model; Physics

Physicists want to determine the most fundamental building blocks of the Universe and how they interact. Currently, our best theory is called the Standard Model (SM). It explains how magnetic fields and electrical currents are related to radioactive nuclei decay and the force that holds a proton together. However, many open questions exist within and beyond the SM. Neither ~95% of the known universe nor gravity is described by the SM, for instance.The SM deals only with the visible Universe, while the majority of matter does not emit or absorb light: aptly named dark matter (DM). By looking at gravitational effects on stars in galaxies and clusters of galaxies, we suspect DM comprises ~84% of the Universe's mass. DM has not yet been observed on Earth because it may interact very weakly with visible matter. Some attempts to explain DM are simple and only include one new particle and mediator - the bridge between the dark and visible worlds. Others, such as Supersymmetry, a very popular SM extension, predict many new particles, one of which could be DM.Gravity is very weak. A kitchen magnet holds a paper clip against the gravitational pull of the entire Earth. One explanation is that the Universe contains more than four dimensions, and we only feel a fraction of the full gravitational potential in our four.As scientists, we develop possible answers to unexplained phenomena, such as those mentioned above, and devise experiments to test our ideas; sometimes we find the completely unexpected. The Large Hadron Collider (LHC) was built for this purpose. The LHC smashes together protons at very high energies to create all the SM particles and hopefully a few never seen before! DM particles themselves or the DM mediator can be created in proton-proton collisions. The higher dimensional theories focusing on gravity predict the creation of black holes at LHC energies. These and a host of other theories tackling the big physics questions, if true, predict new particles will be produced by the LHC and decay into jets - highly energetic collimated sprays of SM particles. An excess in the number of such decays would signify that we have found new physics and revolutionize our understanding of the Universe!With every discovery, the new physics gives insight to the most fundamental workings of the Universe. It changes our understanding of the Universe and the way we live in it. The discovery of the electron allowed us to harness the power of electricity and magnets, understanding the rules of the atom yielded nuclear energy to power our cities, and Einstein's theory of relativity enabled Global Positioning Systems to find our way across this beautiful planet. Technologies developed by physicists have amazing potential for progress, and the World Wide Web for example was created at CERN. Physicists trained in the rigors of the scientific method on tremendous datasets are employed by governments, businesses, financial institutions, and even sports teams to analyze data and solve complicated problems. Nevertheless, for me, the reason to understand nature at a fundamental level is best encapsulated by the Nobel laureate Steven Weinberg when he wrote, "The effort to understand the Universe is one of the very few things which lifts human life a little above the level of farce and gives it some of the grace of tragedy."

物理学家希望确定宇宙最基本的组成部分以及它们如何相互作用。目前，我们最好的理论被称为标准模型（SM）。它解释了磁场和电流是如何与放射性原子核衰变以及将质子结合在一起的力相关的。然而，在SM内部和外部都存在许多悬而未决的问题。例如，SM无法描述95%的已知宇宙和引力，SM只处理可见宇宙，而大多数物质既不发光也不吸收光：被恰当地命名为暗物质（DM）。通过观察星系和星系团中恒星的引力效应，我们怀疑DM占宇宙质量的84%。DM尚未在地球上观测到，因为它可能与可见物质的相互作用非常微弱。一些试图解释DM的尝试很简单，只包括一个新的粒子和介质-黑暗和可见世界之间的桥梁。其他的，如超对称性，一个非常流行的SM扩展，预测了许多新的粒子，其中之一可能是DM。一个厨房磁铁固定着一个回形针，抵抗整个地球的引力。一种解释是宇宙包含四维以上，而我们在四维中只感受到全部引力势的一小部分。作为科学家，我们为无法解释的现象（如上面提到的那些）开发可能的答案，并设计实验来测试我们的想法;有时我们会发现完全出乎意料的结果。大型强子对撞机（LHC）就是为此而建造的。大型强子对撞机在非常高的能量下将质子撞击在一起，创造出所有的SM粒子，希望有一些是以前从未见过的！DM粒子本身或DM介体可以在质子-质子碰撞中产生。聚焦于引力的高维理论预测了在LHC能量下黑洞的产生。这些理论和其他一系列解决重大物理问题的理论，如果是真的，预测新的粒子将由LHC产生，并衰变成喷流-高能量的SM粒子准直喷雾。这种衰变的数量过多意味着我们已经发现了新的物理学，并彻底改变了我们对宇宙的理解！随着每一个发现，新物理学都让我们深入了解宇宙最基本的运作方式。它改变了我们对宇宙的理解和我们生活在其中的方式。电子的发现使我们能够利用电力和磁铁的力量，了解原子的规则产生核能为我们的城市供电，爱因斯坦的相对论使全球定位系统能够在这个美丽的星球上找到我们的路。物理学家开发的技术具有惊人的进步潜力，例如万维网就是在CERN创建的。在大量数据集上接受过严格科学方法训练的物理学家被政府、企业、金融机构甚至体育团队雇用，以分析数据并解决复杂问题。尽管如此，对我来说，从根本上理解自然的原因最好地概括在诺贝尔奖得主史蒂文·温伯格的文章中，他写道：“理解宇宙的努力是极少数几件事之一，它使人类生活稍微超越了闹剧的水平，并赋予它一些悲剧的优雅。"