Theory and collider phenomenology at the electroweak scale

粒子物理学的目标是发现宇宙是由什么组成的，以及它是如何工作的。我们对理解自然的追求已经产生了对物质结构的非常成功的理解，这是由粒子物理学的标准模型描述的。然而，我们知道标准模型是不完整的，原因（至少）有两个：它无法解释引力相对于其他自然力的极端弱点，它无法解释占宇宙质量80%的“暗物质”。此外，标准模型对普通粒子质量起源的解释，即所谓的希格斯机制，仍然未经实验检验。我们现在已经到了一个非常激动人心的时刻，在未来几年的实验中（特别是在大型强子对撞机上，现在在瑞士日内瓦的欧洲核子研究中心运行的第二年），预计将为这些问题提供答案。 我的研究重点是粒子物理学的新理论，超越了我们目前的标准模型，试图解决这些问题。无论是什么导致了质量的起源和引力的极度微弱，它都必须在实验上表现出兆电子伏或以下的尺度。虽然不太确定，但暗物质也有很好的机会在这个能量尺度上被揭示出来。大型强子对撞机就是为了彻底探索这个能量范围而建造的--为了理解这个对撞机产生的数据，我们需要对标准模型中的期望值和各种新模型的潜在信号进行详细的理论计算。这些预期信号的计算，以及对任何新发现的解释，是我研究的重点。这项工作包括制定新的模型，计算粒子内容和相互作用，运行粒子产生事件的模拟，以及开发实验人员可以用来区分真正的新物理信号和熟悉的标准模型背景的策略。

The objective of particle physics is to discover what the universe is made of and how it works. Our quest to understand nature has produced a remarkably successful understanding of the structure of matter, described by the Standard Model of particle physics. However, we know that the Standard Model is incomplete for (at least) two reasons: it fails to explain the extreme weakness of gravity compared to the other forces of nature, and it is unable to account for the "dark matter" that makes up about 80% of the mass in the universe. Also, the Standard Model's explanation for the origin of mass of ordinary particles, the so-called Higgs mechanism, is still experimentally untested. We have come now to a very exciting time when experiments in the next few years (particularly at the Large Hadron Collider, now in its second year of operation at CERN in Geneva, Switzerland) are expected to provide answers to these questions. My research focuses on new theories of particle physics beyond our current Standard Model that try to address these problems. Whatever is responsible for the origin of mass and the extreme weakness of gravity, it must manifest experimentally at or below the tera-electron-volt scale. While less certain, dark matter also has a good chance of being revealed at this energy scale. The Large Hadron Collider was built to thoroughly explore this energy range---in order to understand the data coming out of this collider, we need detailed theory calculations of both the expectations within the Standard Model and the potential signals of a variety of new models. The calculation of these expected signals, and interpretation of any new discoveries as they arise, is the focus of my research. This work involves formulating the new models, working out the particle content and interactions, running simulations of particle production events, and developing strategies that experimenters can use to distinguish genuine new physics signals from the familiar Standard Model backgrounds.