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."

物理学家想要确定宇宙最基本的组成部分以及它们是如何相互作用的。目前，我们最好的理论是标准模型(SM)。它解释了磁场和电流如何与放射性原子核衰变以及将质子聚集在一起的力有关。然而，SM内部和外部存在许多悬而未决的问题。例如，SM既不描述已知宇宙的95%，也不描述引力。SM只描述可见宇宙，而大多数物质不发射或吸收光：暗物质(DM)是一个恰当的名称。通过观察星系和星系团中恒星的引力效应，我们推测Dm约占宇宙质量的84%。地球上还没有观测到DM，因为它可能与可见物质的相互作用非常弱。一些解释DM的尝试很简单，只包括一种新的粒子和介体--黑暗世界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.引力非常弱。厨房磁铁将回形针固定在整个地球的引力作用下。一种解释是，宇宙包含超过四个维度，而我们只感受到四个维度中完整引力势的一小部分。作为科学家，我们对上面提到的那些无法解释的现象提出可能的答案，并设计实验来测试我们的想法；有时我们会发现完全意想不到的东西。大型强子对撞机(LHC)就是为此目的而建造的。大型强子对撞机以非常高的能量将质子撞击在一起，产生了所有的SM粒子，希望还有一些以前从未见过的粒子！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，预测大型强子对撞机将产生新的粒子，并衰变成喷流--高能量的SM粒子的准直喷雾。这种衰变的数量过多将意味着我们已经发现了新的物理，并彻底改变了我们对宇宙的理解！每一次发现，新的物理都会让我们洞察宇宙最基本的工作原理。它改变了我们对宇宙的理解和我们生活在宇宙中的方式。电子的发现使我们能够利用电力和磁铁的力量，了解原子产生核能的规则，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，例如万维网就是在欧洲核子研究中心创立的。政府、企业、金融机构，甚至运动队都雇佣了经过严格科学方法训练的物理学家来分析数据和解决复杂的问题。然而，对我来说，从根本上理解自然的理由用诺贝尔奖获得者史蒂文·温伯格的话最好地概括了，他写道：“理解宇宙的努力是极少数使人类生活略高于闹剧水平并给它带来一些悲剧的优雅的事情之一。”