Particle Physics Consolidated Grant from the University of Sheffield: Energy Frontier, Neutrinos, Dark Matter

谢菲尔德大学粒子物理学综合资助：能源前沿、中微子、暗物质

• 批准号: ST/S000747/1
• 负责人: Davide Costanzo
• 金额: $ 309.32万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FS000747%2F1
• 关键词: Particle; Physics; Consolidated; Grant; University

"What is the Universe made of, and why?" Sheffield's HEP programme aims to address this fundamental question. There are two problems here: about 5/6 of the matter in the Universe seems to be an as yet undiscovered particle (dark matter), and the remaining 1/6 is all matter - not the 50:50 matter-antimatter mix we make in laboratories.We search for the dark matter particle in two ways: at the energy frontier, by seeking to detect new particles created by the high-energy proton-proton collisions of the LHC at CERN, and in direct searches, attempting to observe these particles in the Galaxy itself. The theory of supersymmetry, which predicts a whole set of particles related to, but more massive than, the known particles of the Standard Model (SM), offers a candidate dark matter particle. If supersymmetric particles can be made at the LHC, they should be detected in ATLAS. Our programme searches specifically for new Higgs bosons and for particles related to the SM quarks and gluons. At ATLAS, we also study SM processes involving the force carriers of the weak interaction, probing our understanding of the SM. Looking to the future, we are contributing essential work to the upgrade of the ATLAS experiment required to take full advantage of higher event rates in future running of the LHC.Most of the matter in our Galaxy is dark matter. In the LZ experiment, we search for evidence of dark matter colliding with Xe atoms in the experiment and causing them to recoil. This experiment will be the most sensitive dark matter detector ever constructed. Understanding possible background - non-dark-matter - events is critical to this, and we have world leading expertise in this field. In addition, we are leading the development of directional dark matter detectors, which will be vital in proving that any candidate signal really does come from the Galaxy and not the Earth. We are also the only UK group involved in the search for axions: another possible type of dark matter particle which cannot be detected at the LHC or in standard dark matter experiments.Why is the matter in the Universe all matter, not antimatter? The answer to this question must lie in subtle differences between particles and antiparticles, an effect called CP violation. The CP violating effects so far observed are not nearly large enough to create the Universe we see. The most likely source for more CP violation is in the interactions of neutrinos. A key observation is that neutrinos have mass, and that different types of neutrinos can interchange their identities in flight. The T2K experiment has made measurements of this, and has detected tantalising hints of CP violation. We plan to build on this work, both in running experiments (T2K and SBND) and in designing the next generation of neutrino experiments which will have much greater sensitivity. We have developed tools to assist the neutrino community in comparing results and improving our understanding of how neutrinos interact. Our access to Boulby Mine provides an invaluable low-background laboratory for testing materials and detector prototypes.Last but not least, we seek to apply HEP technology to industry and to solving global problems. We are using techniques developed for ATLAS to contribute to the development of robotics and to deal with highly radioactive environments such as Chernobyl. We are designing muon detectors to search for nuclear contraband and monitor volcanoes. Our signal processing techniques are being applied to improving medical imaging for heart patients. Our expertise in water Cherenkov neutrino detection is being exploited in an experiment designed to monitor compliance with nuclear non-proliferation treaties. All of this work builds on our STFC core programme to benefit the wider world.

“宇宙是什么，为什么？”谢菲尔德的HEP计划旨在解决这个基本问题。 There are two problems here: about 5/6 of the matter in the Universe seems to be an as yet undiscovered particle (dark matter), and the remaining 1/6 is all matter - not the 50:50 matter-antimatter mix we make in laboratories.We search for the dark matter particle in two ways: at the energy frontier, by seeking to detect new particles created by the high-energy proton-proton collisions of the LHC at CERN, and in direct searches,试图观察星系本身中的这些颗粒。超对称的理论预测了一组与标准模型（SM）的已知粒子相关但更大的粒子提供了候选暗物质粒子。如果可以在LHC上制成超对称颗粒，则应在Atlas中检测到它们。我们的程序专门搜索新的希格斯玻色子和与sm夸克和胶子有关的颗粒。在Atlas，我们还研究了涉及弱相互作用的力载体的SM过程，从而探讨了我们对SM的理解。展望未来，我们为在LHC的未来运行中充分利用较高事件的升级所需的升级为基本工作。我们银河系中的大部分都是暗物质。在LZ实验中，我们在实验中寻找与Xe原子相撞的暗物质证据并导致它们后坐力。该实验将是有史以来最敏感的暗物质检测器。理解可能的背景 - 非黑暗事件 - 事件对此至关重要，我们在该领域拥有世界领先的专业知识。此外，我们正在领导定向暗物质探测器的发展，这对于证明任何候选信号确实来自银河系而不是地球至关重要。我们也是参与寻找轴的唯一英国群体：在LHC或标准的暗物质实验中无法检测到的另一种可能的暗物质粒子类型。为什么在宇宙中物质是所有物质，而不是反物质？这个问题的答案必须在于颗粒和反粒子之间的细微差异，这一效果称为CP违规。到目前为止观察到的违反CP违反CP效果还不够大，无法创建我们看到的宇宙。违反CP的最可能来源是中微子的相互作用。一个关键的观察是，中微子具有质量，不同类型的中微子可以在飞行中互换其身份。 T2K实验对此进行了测量，并发现了CP违规的诱人提示。我们计划在运行实验（T2K和SBND）以及设计下微中微子实验的过程中建立这项工作，这些实验将具有更大的灵敏度。我们开发了工具，以帮助中微子社区比较结果并提高我们对中微子相互作用的理解。我们进入布比矿山（Boulby Mine）为测试材料和探测器原型提供了宝贵的低背景实验室。最后，我们试图将HEP技术应用于行业并解决全球问题。我们正在使用为Atlas开发的技术来为机器人技术的开发做出贡献，并处理高度放射性的环境，例如切尔诺贝利。我们正在设计MUON探测器，以寻找核违禁品和监测火山。我们的信号处理技术正在用于改善心脏病患者的医学成像。我们在旨在监测符合核不扩散条约的实验中利用了我们在水Cherenkov中微子检测方面的专业知识。所有这些工作都建立在我们的STFC核心计划上，以使更广泛的世界受益。

项目成果

Search for excited electrons singly produced in proton-proton collisions at $$\sqrt{s} ~=~13~\text {Te}\text {V}$$ with the ATLAS experiment at the LHC

利用大型强子对撞机的 ATLAS 实验，在 $$sqrt{s} ~=~13~ ext {Te} ext {V}$$ 处搜索质子-质子碰撞中单独产生的激发电子

• DOI: 10.1140/epjc/s10052-019-7295-1
• 发表时间: 2019
• 期刊: The European Physical Journal C
• 作者: Aaboud M

Measurements of inclusive and differential fiducial cross-sections of $$t\bar{t}\gamma $$ production in leptonic final states at $$\sqrt{s}=13~\text {TeV}$$ in ATLAS

ATLAS 中 $$sqrt{s}=13~ ext {TeV}$$ 轻子最终状态下 $$tar{t}gamma $$ 产生的包含和微分基准横截面的测量

• DOI: 10.1140/epjc/s10052-019-6849-6
• 发表时间: 2019
• 期刊: The European Physical Journal C
• 作者: Aaboud M

Combination of Searches for Invisible Higgs Boson Decays with the ATLAS Experiment

• DOI: 10.1103/physrevlett.122.231801
• 发表时间: 2019-06-13
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Aaboud, M.;Aad, G.;Zhang, Z.
• 通讯作者: Zhang, Z.

Search for Higgs boson decays into a pair of light bosons in the bbμμ final state in pp collision at s=13TeV with the ATLAS detector

使用 ATLAS 探测器在 s=13TeV 的 pp 碰撞中寻找希格斯玻色子衰变为 bbμμ 最终态的一对轻玻色子

• DOI: 10.1016/j.physletb.2018.10.073
• 发表时间: 2019
• 期刊: Physics Letters B
• 影响因子: 4.4
• 作者: Aaboud, M.;Aad, G.;Abbott, B.;Abdinov, O.;Abeloos, B.;Abhayasinghe, D.K.;Abidi, S.H.;AbouZeid, O.S.;Abraham, N.L.;Abramowicz, H.
• 通讯作者: Abramowicz, H.

Search for four-top-quark production in the single-lepton and opposite-sign dilepton final states in p p collisions at s = 13 TeV with the ATLAS detector

使用 ATLAS 探测器在 s = 13 TeV 的 p p 碰撞中搜索单轻子和相反符号双轻子最终状态中的四顶夸克产生

• DOI: 10.1103/physrevd.99.052009
• 发表时间: 2019
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Aaboud M