Louisiana State University Physics & Astronomy

High Energy Physics

Chan - Haymaker - Metcalf

The high-energy physics group consists of three experimental physicists: Imlay, McNeil, and Metcalf; two theoreticians: Chan and Haymaker; several postdoctoral associates; and a number of technicians, graduate students, and undergraduate student workers. The experimental group has concentrated on colliding beam physics and neutrino physics. Present ongoing experiments include the L3 experiment at LEP and the BooNE neutrino experiment at Fermilab. The group is also involved in preparation for future experiments.

On the theoretical side, work is in progress to construct dynamical models of quark systems and to apply them to the phenomenology of elementary particles. Furthermore, members are investigating the underlying symmetries to better understand the symmetry breaking that gives rise to observed phenomena. Gauge theories, quantum chromodynamics (QCD), effective action expansions, and lattice-gauge theories are all under investigation.

The experimental high-energy program at LSU started in 1979. In the group's first experiment, they studied electron-positron collisions at the Cornell Electron Storage Ring (CESR). The experiments provided important information on the properties of the b quark by studying the upsilon resonances. In other projects, the experimental high-energy group has been involved in the AMY experiment at the TRISTAN electron-positron storage ring in Japan and the ZEUS experiment at the HERA electron-proton collider in Germany.

McNeil is participating in the L3 experiment at the LEP electron-positron collider at the CERN Laboratory in Geneva, Switzerland. Recent upgrades to the LEP accelerator have allowed it to operate in a previously unexplored energy region. LEP is an excellent place to study electro-weak interactions, QCD, and γγ interactions at high energy.

Imlay and Metcalf have played a major role on the LSND neutrino experiment at LAMPF. This experiment is primarily a search for neutrino oscillations; however, it has also contributed significantly to our knowledge of low energy neutrino cross-sections. In fact, the first published result from the experiment, on the cross section near threshold, indicated a major descrepancy with existing theoretical models and has led to much recent work on the process.

By far the most exciting result of LSND to date is the evidence researchers have found for neutrino oscillations. This signal has persisted through three years of data-taking and is clearly not a statistical fluctuation nor a cosmic-ray background. If subsequent work confirms that it is indeed due to neutrino oscillations, it will have profound implications not only for the standard model of particle physics but also for many areas of astrophysics. An experiment (BooNE) to test the LSND result at Fermilab is now being constructed with participation by LSU.

The experimental high-energy group is also involved in experiments that are in the design and/or construction phase. These experiments include a future neutrino experiment, forthcoming experiments at the Large Hadron Collider at CERN and astroparticle physics experiments in space.

Updated: Wed, 02-Apr-2008 9:26 AM