AN Underground Belayed In-Shaft experiment to search for long-lived particles using LHC service shafts at CERN

欧洲核子研究中心利用大型强子对撞机服务井进行地下保护井内实验，寻找长寿命粒子

基本信息

批准号：
MR/V023098/1
负责人：
Oleg Brandt
金额：
$ 194.59万
依托单位：
University of Cambridge
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：
未结题

来源：
https://gtr.ukri.org/projects?ref=MR%2FV023098%2F1
关键词：
Underground Belayed Shaft experiment search

项目摘要

The Standard Model of Elementary Particle Physics (SM) is the deepest, mostcomplete and accurate scientific theory and has passed decades of experimentaltests. Yet, it cannot answer many fundamental questions. These include:- the nature of Dark Matter, which contributes 80% of the total mass in the Universe, - the puzzle of neutrino particles from e.g. nuclear reactions that are predicted to be massless by the SM but are experimentally known to have a very small albeit non-zero mass, and - the riddle of the origin of the matter-antimatter asymmetry that would explain why the Universe -- as we know it -- is composed of matter rather than antimatter,- etc.Many proposed theoretical scenarios that address these fundamental questionspredict new, electrically neutral particles with long lifetimes on the scalethat can be probed by typical collider experiments like ATLAS or CMS at theLarge Hadron Collider (LHC) of CERN. Yet, there is a striking gap insensitivity for such long-lived particles that are electrically neutral andhave a mass above 1 Gigaelectronvolt (GeV), i.e., are more massive than ahydrogen atom. This sensitivity gap spans several orders of magnitude in thelifetimes, which translates into decay lengths from 100 m and up to theBig-Bang nucleosynthesis bound of 100,000,000 m, quite reasonably assuming theparticles move at the speed of light when produced at the LHC.This proposal aims to close the present gap in sensitivity to long-livedparticles in a timely manner and at up to one order of magnitude lower coststhan proposals with competing sensitivity, resulting in a transformative impacton the field. This can be achieved by instrumenting the existing service shaftsof the ATLAS experiment at the Large Hadron Collider (LHC) of CERN. Theforeseen detector structure, AN Underground Belayed In-Shaft search experiment(ANUBIS), will consist of a number of tracking stations belayed into the shaftand affixed to its walls, instrumenting approximately 15,000 m^3 with dedicatedtracking detectors with excellent timing capability. For scenarios withelectrically neutral long-lived particles with masses above 1 GeV, the lifetimereach is increased by a factor of up to 1,000 compared to currently operatingand approved future experiments. To master this challenge cost-effectively,the tracking stations of ANUBIS will employ the next generation of detectorsusing the resistive plate chamber (RPC) technology that I will develop in theproposed FLF project using the low-cost, large-scale specifications of ANUBIS. In addition to the ambitious research programme above, another importantobjective is to expand the full potential of the existing ATLAS detector tosearch for long-lived particles on a short time scale. The detector technology that I will develop in the proposed FLF project usingthe low-cost, large-scale specifications of ANUBIS is an ideal candidate forthe scanning of buildings, bridges, and other large-scale infrastructure usingmuon tomography based on naturally occurring cosmic rays. Cosmic ray tomographyprovides crucial advantages over currently available approaches that sufferfrom a limited depth reach and resolution (radar), are expensive and carrysignificant health and safety risks (X-ray), or even prohibitive (destructivemethods). Preliminary research reveals a wide range of applications, given thelarge number of ageing buildings and infrastructure constructed in the 1950-70swith questionable structural integrity. The environmental human footprint canbe dramatically reduced by using existing structures for longer in a safemanner, which, combined with substantial cost savings, will enormously benefitour society. One of the main goals of the FLF proposal is to realise afull-scale demonstrator prototype for cosmic ray tomography including fieldtests, with an intermediate-term goal of commercialisation.

基本粒子物理标准模型（SM）是最深刻、最完整、最准确的科学理论，经过了数十年的实验检验。然而，它无法回答许多基本问题。其中包括： - 暗物质的性质，它占宇宙总质量的 80%， - 来自例如中微子粒子的谜题。 SM 预测核反应是无质量的，但实验上已知其质量非常小，尽管非零，并且 - 物质-反物质不对称性起源之谜，这将解释为什么宇宙 - 正如我们所知它——由物质而不是反物质组成，等等。解决这些基本问题的许多提出的理论场景都预测了具有长寿命的新的电中性粒子，可以通过典型的对撞机实验（如 ATLAS 或 CMS）进行探测。欧洲核子研究中心的大型强子对撞机（LHC）。然而，对于这种电中性且质量超过 1 吉电子伏 (GeV)（即比氢原子质量更大）的长寿命粒子来说，存在显着的间隙不敏感性。这种灵敏度差距在生命周期中跨越了几个数量级，这转化为从 100 m 到大爆炸核合成界限 100,000,000 m 的衰变长度，相当合理地假设粒子在大型强子对撞机中产生时以光速移动。该提案的目的及时缩小目前对长寿命粒子的敏感性差距，并且成本比具有竞争性敏感性的提案低一个数量级，从而对该领域产生变革性影响。这可以通过在欧洲核子研究组织大型强子对撞机 (LHC) 的 ATLAS 实验的现有服务轴上安装仪器来实现。预期的探测器结构，即地下栓系井内搜索实验 (ANUBIS)，将由多个系在井中并固定在井壁上的跟踪站组成，在大约 15,000 m^3 的范围内配备具有出色计时能力的专用跟踪探测器。对于质量超过 1 GeV 的电中性长寿命粒子的情况，与目前正在运行和批准的未来实验相比，寿命范围增加了 1,000 倍。为了经济高效地应对这一挑战，ANUBIS 的跟踪站将采用采用电阻板室 (RPC) 技术的下一代探测器，我将在拟议的 FLF 项目中使用 ANUBIS 的低成本、大规模规格开发该技术。除了上述雄心勃勃的研究计划之外，另一个重要目标是扩展现有 ATLAS 探测器的全部潜力，以在短时间内寻找长寿命粒子。我将在拟议的 FLF 项目中使用 ANUBIS 的低成本、大规模规格开发的探测器技术，是使用基于自然发生的宇宙射线的μ介子断层扫描扫描建筑物、桥梁和其他大型基础设施的理想候选技术。与目前可用的方法（雷达）相比，宇宙射线断层扫描具有重要的优势，这些方法的深度范围和分辨率（雷达）有限，价格昂贵且存在重大的健康和安全风险（X射线），甚至令人望而却步（破坏性方法）。鉴于 1950-70 年代建造的大量老化建筑和基础设施结构完整性值得怀疑，初步研究揭示了其广泛的应用。通过以安全的方式更长时间地使用现有结构，可以大大减少人类对环境的影响，再加上大量的成本节约，将极大地造福我们的社会。 FLF提案的主要目标之一是实现宇宙射线断层扫描的全尺寸演示原型，包括现场测试，并实现商业化的中期目标。