Widening the search for Dark Matter and Physics beyond the Standard Model with direct detection experiments

通过直接探测实验将暗物质和物理学的搜索范围扩大到标准模型之外

• 批准号: ST/R003181/2
• 负责人: James Dobson
• 金额: $ 12.87万
• 依托单位: King's College London
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FR003181%2F2
• 关键词: Widening; search; Dark; Matter; Physics

Everything we can see in the Universe is only a small fraction of its mass. Most of it, an incredible 85%, is 'dark' - and we know remarkably little about it. We can infer the role of this mysterious 'Dark Matter' in the early Universe when it allowed galaxies to form and we can observe its gravitational effects today as it holds the galaxies, including our own, together. Yet we cannot see it directly and have yet to make any detection that helps us understand its nature. Put simply, we know Dark Matter is there, but we do not know what it is! What we do know is that the Standard Model of particle physics that explains so accurately most of what we do observe cannot help us - it provides no candidates that fit the bill. The detection of Dark Matter will not only tell us what much of our Universe is made of, it will also open the door to physics beyond the Standard Model, bringing down the veil between us and a deeper understanding of the Universe and our place within it. The effort to detect Dark Matter is worldwide - it is truly one of the most important scientific missions of our time.Piecing together all the evidence, our best theories tell us Dark Matter is made up of tiny particles that that pervade the Universe but rarely interact - millions of Dark Matter particles are passing harmlessly through you as you read this right now. Just occasionally one of them may bounce off the nucleus of an atom, giving it a tiny kick of energy. Observing such a 'direct' scatter is the only way to be sure that we have seen Dark Matter from our own galaxy; born in the Big Bang and present ever since. But to have any hope of seeing such tiny, rare signals requires experiments like no other: large detectors, sensitive to the recoil of a single atom, constructed from the most radio-pure materials and buried deep under the surface of the Earth.LUX-ZEPLIN (LZ) will be the largest and most advanced experiment ever built in the direct search for Dark Matter. LZ will come online in 2019 and operate for 3 years in a former gold mine turned science laboratory 1.5 km underground in S. Dakota, USA. I am a leading researcher in the LZ experiment, responsible for the simulations that helped us to design it; that model the level of 'background' from Standard Model processes that may mask Dark Matter signatures; and that establish the experiment's science reach. LZ will be over 10 times more sensitive than earlier experiments and its unprecedented scale and ultra-low background environment will herald a new era in direct searches. In addition to exploring the bulk of the remaining uncharted territory in search of Weakly Interacting Massive Particles (WIMPs), the most popular candidate for dark matter, LZ will now have sensitivity and discovery potential to a whole host of equally well-motivated alternative (non-WIMP) Dark Matter candidates and other physics beyond the Standard Model. Key to these searches is my expertise in modelling background processes, in exploiting multiple signal channels across the full energy range available to LZ, and in developing software to recognise complex signals from wholly unexpected physics. I will take leading roles in the WIMP and alternative model searches from LZ to uncover groundbreaking discoveries.Alongside physics analyses and software, I have developed new hardware capability in the UK with world-class mass-spectrometry to measure trace radioactivity in materials. This technique is crucial to building any future experiment needed to confirm discovery, perform high-precision measurements of signal, or explore the last of the available parameter space available for WIMPs. Such an experiment would have incredible sensitivity to the alternative models and beyond Standard Model physics, such as neutrino-less double beta decay. My mass-spectrometry research will meet the stringent radio-purity needs for future generation experiments and feed the background model upon which all the science rests.

我们在宇宙中看到的一切都只是其质量的一小部分。其中大部分（令人难以置信的 85%）是“黑暗的”——而我们对此知之甚少。我们可以推断这种神秘的“暗物质”在早期宇宙中的作用，当它允许星系形成时，我们今天可以观察到它的引力效应，因为它将包括我们自己的星系在内的星系保持在一起。然而我们无法直接看到它，也尚未进行任何检测来帮助我们了解其本质。简而言之，我们知道暗物质存在，但我们不知道它是什么！我们所知道的是，粒子物理学的标准模型能够如此准确地解释我们所观察到的大部分现象，但它无法帮助我们——它没有提供符合要求的候选模型。暗物质的探测不仅会告诉我们宇宙是由什么组成的，还将打开标准模型之外的物理学之门，揭开我们之间的面纱，更深入地了解宇宙和我们在宇宙中的位置。探测暗物质的努力是全世界范围内的——这确实是我们这个时代最重要的科学任务之一。将所有证据拼凑在一起，我们最好的理论告诉我们，暗物质是由遍布宇宙但很少相互作用的微小粒子组成的- 当您现在阅读本文时，数以百万计的暗物质粒子正在无害地穿过您。偶尔，其中一个可能会从原子核上弹开，给原子核带来微小的能量。观察这种“直接”散射是确保我们从自己的星系中看到暗物质的唯一方法。诞生于大爆炸并从那时起一直存在。但要想看到如此微小、罕见的信号，就需要进行与其他实验不同的实验：大型探测器，对单个原子的反冲敏感，由无线电纯净材料制成，深埋在地球表面以下。 ZEPLIN (LZ) 将是迄今为止在直接寻找暗物质方面规模最大、最先进的实验。 LZ 将于 2019 年上线，并在美国南达科他州地下 1.5 公里处由金矿改造而成的科学实验室运行 3 年。我是 LZ 实验的首席研究员，负责帮助我们设计它的模拟；对标准模型过程中可能掩盖暗物质特征的“背景”水平进行建模；并确立了该实验的科学影响力。 LZ的灵敏度将比早期实验高出10倍以上，其前所未有的规模和超低背景环境将预示着直接搜索的新时代。除了探索大部分剩余的未知领域以寻找弱相互作用大质量粒子（WIMP）（暗物质最受欢迎的候选者）之外，LZ 现在将对一整套同样有充分动机的替代品（非-WIMP）暗物质候选者和标准模型之外的其他物理学。这些搜索的关键是我在建模背景过程、在 LZ 可用的整个能量范围内利用多个信号通道以及开发软件来识别来自完全意想不到的物理现象的复杂信号方面的专业知识。我将在 WIMP 和 LZ 的替代模型搜索中发挥主导作用，以发现突破性的发现。除了物理分析和软件之外，我还在英国开发了新的硬件功能，采用世界一流的质谱仪来测量材料中的痕量放射性。这项技术对于构建任何未来所需的实验至关重要，以确认发现、执行信号的高精度测量或探索可用于 WIMP 的最后一个可用参数空间。这样的实验将对替代模型和标准模型物理之外的模型具有令人难以置信的敏感性，例如无中微子双贝塔衰变。我的质谱研究将满足下一代实验严格的无线电纯度需求，并为所有科学所依赖的背景模型提供支持。

项目成果

Background determination for the LUX-ZEPLIN dark matter experiment

LUX-ZEPLIN 暗物质实验的背景测定

• DOI: http://dx.10.1103/physrevd.108.012010
• 发表时间: 2023
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Aalbers J

Nuclear recoil response of liquid xenon and its impact on solar 8B neutrino and dark matter searches

液态氙的核反冲响应及其对太阳 8B 中微子和暗物质搜索的影响

• DOI: http://dx.10.1103/physrevd.108.022007
• 发表时间: 2023
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Xiang X

Search for new physics in low-energy electron recoils from the first LZ exposure

从第一次 LZ 暴露中寻找低能电子反冲的新物理

• DOI: http://dx.10.1103/physrevd.108.072006
• 发表时间: 2023
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Aalbers J