Aida X El-Khadra

Professor

Ph.D., Physics, University of California, Los Angeles, 1989

Professor Aida El-Khadra received her PhD. in 1989 from the University of California, Los Angeles, after receiving her diplom from Freie Universitaeät, Berlin, Germany. She held postdoctoral research appointments at Fermi National Accelerator Laboratory, Brookhaven National Laboratory, and The Ohio State Univerity before joining the Illinois faculty in 1995.

Prof. El-Khadra is a leader of one of the most successful lattice QCD groups in the world. Low-energy strong interaction physics cannot be analyzed perturbatively; our only recourse has been numerical simulation using the lattice formulation of quantum chromodynamics (QCD). For almost 20 years this field produced very little that was useful to others outside the field. This unfortunate situation has changed dramatically over the past several years, and Prof. El-Khadra and her collaborators have played a central role in this renaissance. Their accomplishments include the first correct analysis of standard lattice actions when applied to heavy quarks (central to most serious lattice studies of heavy-quark weak-interaction phenomenology); the first serious attempt at obtaining the strong-interaction coupling constant from lattice simulations (now the most accurate way to determine the fundamental parameter of strong-interaction physics); a new lattice formulation of quark dynamics that works well for both light and heavy quarks; and careful determinations of the light-quark masses using lattice simulations. This work emphasizes practical applications of lattice QCD—for example, to the sorts of problems of central interest to the next generation of B-factories, at SLAC, KEK and CESR—and so is at the center of the most important area of lattice QCD research.

Other Activities

Elementary Particle Theory
The high-energy theory group has a wide variety of research interests. Topics include the top quark, electroweak symmetry breaking, quantum chromodynamics and lattice field theory, standard-model phenomenology, dynamical supersymmetry breaking, duality in supersymmetric field theory and string theory, M theory, and grand unification.

Standard Model Phenomenology with Lattice QCD
Quantum chromodynamics (QCD), the theory of the strong interactions, is amenable to perturbative calculations only at high energies. A quantitative understanding of the low-energy behavior of QCD, like the interactions of quarks inside hadrons, requires nonperturbative methods. Lattice field theory offers a systematic approach to solving QCD nonperturbatively. The space-time continuum is replaced by a discrete lattice. Part of our research is concerned with improvements in the formulation of lattice QCD. Other projects deal with applications of lattice QCD to phenomenologically interesting processes that yield insight into the standard model of particle physics.

Honors and awards:

• Beckman Fellow in the Center for Advanced Study, 1998-99
• Xerox for Faculty Research Award, 1998
• A. P. Sloan Foundation Fellow, 1997-2000
• Collins Award for Innovative Teaching, COE, 2000
• DOE Outstanding Junior Investigator Award, 1996-2000

Selected Publications:

• C. Aubin, et al. Charmed-meson decay constants in three-flavor lattice QCD. Phys. Rev. Lett. 95, 122002-1-5 (2005).
• C. Aubin, et al. Semileptonic decays of D mesons in three-flavor lattice QCD. Phys. Rev. Lett. 94, 011601-1-5 (2005).
• C. T. H. Davies, et al. High-precision lattice QCD confronts experiment. Phys. Rev. Lett. 92, 022001-1-5 (2004).