David Tucker-Smith

Assistant Professor of Physics

at Williams since 2003


Education/Experience

Contact information

Courses taught 2003-2004

Research interests

The standard model of particle physics, which describes the electromagnetic, weak, and strong interactions of quarks and leptons, has been amazingly successful at explaining data from particle collider experiments. Yet it is regarded as an incomplete theory for a variety of reasons. One important reason is that the dynamics of the standard model tend to drive the scale of electroweak symmetry breaking to be very large, so that to explain the experimentally measured values of the W and Z gauge boson masses requires an extreme (and to many, unbelievable) fine-tuning among certain parameters of the theory. This apparent problem - called the hierarchy problem - has motivated some of the most promising extensions standard model. In my research I study the structure and phenomenology of these extensions. We don't know what new physics will emerge at higher energies to resolve the hierarchy problem, and so different extensions have vastly different features. One class of models incorporates a new symmetry relating fermions and bosons, called supersymmetry, and some theories even involve extra spacetime dimensions. Others simply offer a completely different picture of the Higgs sector, the part of the theory responsible for electroweak symmetry breaking, than that given in the standard model. One common ingredient is that theories that address the hierarchy problem almost always predict new physics that can be probed at energy scales accessible to future colliders, such as the Large Hadron Collider at CERN.

Most recently I have worked with my collaborators on grand unified theories with warped extra dimensions, which have a number of striking differences compared with four-dimensional unified theories. In particular, the ability to probe unification directly is improved in these models because the warped scenario predicts light states whose quantum numbers are characteristic of the unified symmetry, whereas in most four-dimensional theories these states are enormously heavy. I have also been interested in so-called "little Higgs" theories, a new class of models of electroweak symmetry breaking that casts the Higgs as a pseudo-Goldstone boson.

Selected publications


Williams College, Department of Physics