The High Energy Physics (HEP) group consists of four faculty members who perform experimental research and three faculty members who perform theoretical research, as well as several postdoctoral research fellows, and a number of graduate students.
The goals of the experimental high energy physics group are to search for new physics and to explore the predictions of the Standard Model to unprecedented accuracy. In order to perform this research, we are involved in the DØ experiment at Fermilab, and the ATLAS experiment at the Large Hadron Collider (LHC) at CERN. The DØ experiment, located at the Fermilab Tevatron, currently takes data at the highest energy accelerator in the world, while the ATLAS experiment, located at CERN, an international research facility near Geneva Switzerland, is scheduled to begin taking data in 2007, and will supplant Fermilab as the world's highest energy collider.
A computer reconstruction of a top quark decay in the DØ detector at the Fermilab Tevatron.
At the Tevatron, the collisions between the counter-rotating protons and anti-protons allow us to study the strong (QCD) and electroweak interactions through the decays of the produced particles and through their measured angular distributions. Some of the results from the DØ experiment include the discovery of the top quark, precision measurements of the W mass and gluon radiation interference effects, measurement of the properties of heavy mesons including particle-antiparticle mixing, and measurements of the properties of the proton. In addition, numerous searches for new particles, new forces and discrepancies with the Standard model are all been carried out.
We are currently involved with the final installation and testing of the inner detector components for the ATLAS detector. With the completion of the ATLAS detector and the LHC our research emphasis is expected to focus on the physics data coming from CERN, with the possibility of discovering currently unknown physics. It is expected that CERN will discover the final particle predicted by the standard model, the Higgs particle which provides the mechanism to generate massive particles.
Besides the direct physics research, we have been involved in state-of-the-art detector development for DØ and the ATLAS experiment. This program, which uses our own facilities at OU, focuses on advanced silicon micro-strip detectors. The excellent position resolution of silicon allows identification of short lived particles and allows us to measure their properties.
A diagram of a silicon microstrip detector used to find and identify particles with lifetimes of about 1 ps. The majority of particles with this lifetime are composed of b-quarks. Identifying these particles will be useful in the search for the Higgs boson since its dominant decay mode is to these particles.
Our experimental group is also participating in the developments of grid computing technologies for high energy physics and other applications. Because current experiments produce such a large quantity of data, distributed computing is required to analyze the large datasets. HEP experiments are leading the way in developing grid capabilities to deal with this data.
The theoretical group is studying nonperturbative aspects of quantum field theory (QFT) and gauge theories. QFT is the basic framework for the description of particle physics, as well as for many other areas of physics. The calculations required today to solve field theories cannot be done by considering relatively small corrections (perturbations) to noninteracting theories of quarks and gluons, for example. In particular, nonperturbative methods are essential to understand the phenomena of strong interactions. Thus new mathematical methods are required, some of which are being developed by our group. In addition to developing new types of nonperturbative expansions and approximation methods, as well as studying new types of quantum field theories, analytical calculations are being applied to a number of important particle physics topics: quantum chromodynamics, quantum electrodynamics, the Casimir effect (vacuum fluctuations), and various applications. In addition, new theoretical work on magnetic monopole production and binding is being carried out.
Another major focus of our theoretical research is phenomenology of electroweak symmetry breaking, supersymmetric grand unification, CP violation, dark matter, cosmology, and theories with extra dimensions. We investigate direct and indirect signatures of new physics beyond the Standard Model in present and future experiments. In addition, we are employing particle physics to explain interesting astrophysical and cosmological phenomena as well as applying astrophysical and cosmological observations to test and constrain particle theories.
