Quantum Fields and Physics Beyond the Standard Model

现代粒子物理学面临着一幅矛盾的画面。一方面，实验数据已经导致对“标准模型”（SM）的非常精确的验证，包括2012年在大型强子对撞机（LHC）上发现希格斯玻色子。另一方面，观测宇宙学在定量方面的巨大进步表明，尽管它取得了成功，但在宇宙学尺度上，还有很多东西是SM无法解释的，最突出的是暗物质。这些经验上的困惑，再加上关于SM的其他结构问题，激发了多个方向的进一步理论工作：分析广泛的渠道以寻找新的物理学;同时更深入地探索SM的主要结构，以更好地理解其成功并开发新机制的应用。这种双重视角推动了我的两个长期研究目标。 第一个长期目标是更好地理解宇宙中物质含量的起源。我目前的重点是场景和检测渠道的经验动机物理超越标准模型，特别是暗物质。证据指向一个框架，其中暗物质是隐藏（或暗）部门的一部分，弱耦合到SM。研究目标包括使用系统有效场论技术，利用高精度和高光度的实验，这往往是间接敏感的范围更广的能量尺度比直接实现在高能对撞机。要解决的问题包括如何探索低质量暗物质候选者的可行参数空间，或者直接在地下实验室中，使用中等能量的固定目标实验和对撞机，或者间接通过宇宙学，星系和恒星物理学的观察;以及什么机制决定了宇宙中物质和反物质之间的遗迹不对称性（这需要新的“违反CP”的相互作用）。 该计划的第二个长期目标旨在进一步了解量子（规范）场论，SM的基石。这在基础层面以及开发新的计算工具来描述热或非平衡状态下的物质都很重要。所提出的研究的一个方面集中在有限温度下的场论的实时动态行为，其中近平衡可以用流体力学来描述。一个具体的目标是发展的流体力学制度的场论的理解，使用有效的量子场论的工具。这有一系列潜在的应用，但一个重要的（激励）场景是QCD的强相互作用动力学（强核相互作用的规范理论），在RHIC和LHC等实验中探索的区域中碰撞重离子。

Modern particle physics faces a conflicted picture. On one hand, experimental data has led to a remarkably precise verification of the `Standard Model' (SM), including the discovery of the Higgs boson at the Large Hadron Collider (LHC) in 2012. On the other hand, tremendous quantitative advances in observational cosmology show that, despite its success, there is much that the SM cannot explain on cosmological scales, most prominently dark matter. Such empirical puzzles, combined with other structural questions about the SM, motivate further theoretical work in multiple directions: to analyze a wide range of channels in search of new physics; and at the same time to explore and the primary structures of the SM in greater depth, to better understand its success and develop applications to new regimes. This dual perspective drives my two long-term research goals. The first long term goal is to better understand the origin of the matter content in the universe. My current focus is on scenarios and detection channels for empirically motivated physics beyond the Standard Model, specifically dark matter. Evidence points to a framework in which dark matter is part of a hidden (or dark) sector, weakly coupled to the SM. Research objectives include the use of systematic effective field theory techniques to exploit high precision and high luminosity experiments, which are often indirectly sensitive to a much wider range of energy scales than are directly achievable at high energy colliders. Questions to be addressed include how to explore the viable parameter space of low mass dark matter candidates, either directly in underground labs, using medium-energy fixed-target experiments and colliders, or indirectly through observations of cosmology, the galaxy, and stellar physics; and what mechanism determines the relic asymmetry between matter and antimatter in the universe (which requires new "CP-violating" interactions). The second long term goal of this program aims to further our understanding of quantum (gauge) field theories, the building blocks of the SM. This is important at both a foundational level, and also for developing new calculational tools to describe matter in thermal or non-equilibrium regimes. One aspect of the proposed research focuses on the real-time dynamical behaviour of field theories at finite temperature, which near equilibrium can be described using hydrodynamics. A specific objective is to develop the field theoretic understanding of the hydrodynamic regime, using the tools of effective quantum field theory. This has a range of potential applications, but an important (motivating) scenario is the strongly-interacting dynamics of QCD (the gauge theory of the strong nuclear interactions), in regimes that are explored in experiments such as RHIC and the LHC which collide heavy ions.