High Energy Physics Research at |
A computer reconstruction of a top quark decay in the DØ detector at the Fermilab Tevatron. |
The High Energy Physics (HEP) group consists of four faculty members (Abbott, Guttierrez, Skubic and Strauss) who perform experimental research and four faculty members (Baer, Kantowski, Kao and Milton) who perform theoretical research, as well as several postdoctoral research fellows, and other personnel supporting research including a research scientist, an IT specialist, and an engineer.
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 (near Chicago) and the ATLAS experiment at the Large Hadron Collider (LHC) at CERN. While DØ continues to analyze data, the ATLAS experiment is taking data and should continue to be one of the premiere instruments for scientific discovery for decades to come.. More
The DØ experiment analyzes data taken at the Fermilab Tevatron with the world's highest energy proton antiproton collisions, which can be used to study the strong (QCD) and electroweak interactions through the decays of the produced particles and through their measured angular distributions. Some of the recent results from the DØ experiment include the discovery of the top quark, a precision measurement of the W mass, and gluon radiation interference effects. In addition, numerous searches for new particles, new forces and discrepancies with the Standard Model are all being carried out. For the next few years new physics discoveries will continue to be pursued at one of the premier detectors in the world.
The LHC is the highest energy proton-proton collider ever constructed, eventually with a collision energy of 14 TeV. These energetic collisions are expected to probe some of the most fundamental questions in the universe. Questions regarding the origin of mass, the dark matter in the universe, and the abundance of matter over anti-matter may be answered at the LHC. We will look for more fundamental structure within the quarks and leptons that make up our universe and probe fundamental questions about supersymmetry, string theory, and extra dimensions. Though definitive answers to these questions are far from certain, the energy and collision rate of the LHC should make it one of the most exciting scientific tools ever built by humans.
Besides the direct physics research, we have also been involved in state-of-the-art detector development for the 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.
The theoretical group is studying nonperturbative aspects of quantum field theory (QFT) and gauge theories. More
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 non-interacting theories of quarks and gluons, for example. In particular, non-perturbative methods are essential to understand the phenomena of strong interactions. Thus new mathematical methods are required, some of which are being developed in our group. In addition to developing new types of perturbative 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).
A major focus of our HEP theory group is at the theory/experiment interface, called phenomenology. Theorists are investigating QCD, the electroweak theory, and prospects for the detection of Higgs bosons at colliding beam machines such as the LHC and the future International Linear Collider. We are also active in exploring physics ideas that go beyond the Standard Model, such as grand unified theories, supersymmetry, string theory and the possibility of extra spacetime dimensions. Theorists in our group have been pioneers in calculating production and decay rates for new superparticle matter states at LHC and other colliders. We also examine ideas at the particle physics/cosmology interface, especially issues such as dark matter candidate particles and their production in the early universe, and dark matter detection at underground or space-based facilities.