Theory and collider phenomenology at the electroweak scale

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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.