New Approaches to Beyond Standard Model Searches with Colliders and Cosmology

利用对撞机和宇宙学超越标准模型搜索的新方法

• 批准号: SAPIN-2018-00032
• 负责人: Curtin, David
• 金额: $ 3.64万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=690055
• 关键词: New; Approaches; Beyond; Standard; Model

The Large Hadron Collider (LHC) era presents us with a puzzle. Extensions to the Standard Model (SM) are as urgently needed as ever, but none of the canonically expected signals have shown up so far. Resolving this conundrum requires new perspectives on what types of signals are theoretically motivated and new approaches to experimental searches. This challenge and opportunity provides the unifying theme of my research in phenomenology.******Long-lived particles (LLPs) produced at colliders generically arise in many Beyond SM (BSM) scenarios and could reveal the secrets of naturalness, dark matter, and baryogenesis. In the past, the focus on signals inspired by minimal supersymmetry meant that LLPs received much less attention. This is now changing, in significant part due to my work. I am spearheading research into LLP signals at the LHC and am collaborating with experimentalists and theorists to help determine the roadmap of BSM searches for the coming decade.******Born from these investigations is our MATHUSLA detector proposal, which can increase LHC sensitivity to LLP signals by three orders of magnitude. Progress has been swift, and I am now helping to lead the efforts of over 100 theorists and experimentalists to make this idea a reality. Given MATHUSLA's potential for discovery the importance of this endeavor cannot be overstated, making it a major focus for me in the coming years. It also represents a unique opportunity for Canada to take on a leadership position in fundamental particle physics.******The discovery of the Higgs boson has opened up many exciting avenues of investigation for both SM and BSM physics.******Hidden Sectors can lead to a plethora of as-yet undetected collider signals, modify cosmology and even impact astrophysics. They are theoretically motivated for a variety of top-down and bottom-up reasons, but recently their potential to address the hierarchy problem has come into focus. Exotic Higgs decays are a unique portal to these theories at the LHC. Theories of Neutral Naturalness lead to spectacular LLP signals and are a major motivation for their study, but many aspects of their nonperturbative dynamics, theoretical UV completions, and cosmological consequences are not understood.******Study of the Higgs also allows us to begin probing the Electroweak Phase Transition, which is of fundamental importance for our understanding of cosmology, and may play a role in explaining the universe's matter-antimatter asymmetry via the mechanism of Electroweak Baryogenesis. This requires the introduction of new theoretical tools to deal with challenging aspects of Finite-Temperature Quantum Field Theory. Only by making calculations robust and model-independent can we conclusively discover or exclude these and other important theoretical ideas.******Finally, many BSM scenarios can only be probed at future colliders, and articulating this physics case will determine the future of our field in the coming decades.

大型强子对撞机（LHC）时代给我们带来了一个难题。标准模型（SM）的扩展与以往一样迫切需要，但到目前为止还没有出现任何规范预期的信号。解决这个难题需要对理论上激发什么类型的信号有新的视角，以及实验搜索的新方法。这一挑战和机遇为我的现象学研究提供了统一的主题。 *****对撞机产生的长寿命粒子 (LLP) 通常出现在许多 Beyond SM (BSM) 场景中，可以揭示自然、暗物质和重子发生的秘密。过去，对受最小超对称性启发的信号的关注意味着 LLP 受到的关注要少得多。现在这种情况正在改变，很大程度上是由于我的工作。我正在带头研究 LHC 的 LLP 信号，并与实验学家和理论家合作，帮助确定未来十年 BSM 搜索的路线图。****** 从这些研究中诞生了我们的 MATHUSLA 探测器提案，它可以将 LHC 对 LLP 信号的灵敏度提高三个数量级。进展很快，我现在正在帮助领导 100 多名理论家和实验家的努力，使这个想法成为现实。鉴于 MATHUSLA 的发现潜力，这一努力的重要性怎么强调都不为过，这使其成为我未来几年的主要关注点。这也代表了加拿大在基础粒子物理学领域占据领导地位的独特机会。******希格斯玻色子的发现为 SM 和 BSM 物理学开辟了许多令人兴奋的研究途径。******隐藏扇区可以导致大量尚未被发现的对撞机信号，修改宇宙学，甚至影响天体物理学。从理论上讲，它们的动机有多种自上而下和自下而上的原因，但最近它们解决层次结构问题的潜力引起了人们的关注。奇特的希格斯衰变是大型强子对撞机中这些理论的独特门户。中性自然理论导致了壮观的 LLP 信号，并且是其研究的主要动机，但其非微扰动力学、理论 UV 完成和宇宙学后果的许多方面尚不清楚。****** 对希格斯玻色子的研究还使我们能够开始探索电弱相变，这对于我们理解宇宙学至关重要，并且可能在解释宇宙的运行过程中发挥作用。 通过电弱重子发生机制实现物质-反物质不对称。这需要引入新的理论工具来解决有限温度量子场论的挑战性问题。只有通过使计算稳健且独立于模型，我们才能最终发现或排除这些和其他重要的理论思想。 *****最后，许多 BSM 场景只能在未来的对撞机上进行探索，阐明这一物理案例将决定我们领域未来几十年的未来。