Aida X El-Khadra



Aida X El-Khadra

Primary Research Area

  • High Energy Physics
429 Loomis Laboratory


Professor Aida El-Khadra received her PhD. in 1989 from the University of California, Los Angeles, after receiving her diplom from Freie Universitaet, Berlin, Germany. She held postdoctoral research appointments at Brookhaven National Laboratory, Fermi National Accelerator Laboratory, and the Ohio State Univerity before joining the Illinois faculty in 1995. El-Khadra is a fellow of the American Physical Society, a recipient of the Department of Energy's Outstanding Junior Investigator Award, and a Sloan foundation fellow. In addition to a number of other research and teaching awards she has also been named a Fermilab Distinguished Scholar. Service highlights include membership on the APS Division of Particles and Fields (DPF) executive committee (an elected position), APS fellowship committees, chair of the USQCD Scientific Program Committee and member of the USQCD Executive Committee, co-chair of the Muon g-2 Theory Initiative, as well as organizing and advisory committees for international workshops and conferences.

Prof. El-Khadra's area of research is theoretical particle physics. Her research focuses on the application of lattice Quantum Chromodynamics (also called the strong interactions) to phenomenologically interesting processes in flavor physics, which are relevant to the experimental effort at the so-called intensity frontier. She is a leader of one of the most successful collaborations working in Lattice Field Theory in the world, the Fermilab Lattice collaboration. Select highlights include the first quantitative determination of the the strong coupling from lattice QCD, a new formulation of heavy quarks on the lattice that is the foundation of many important, phenomenologically relevant lattice calculations, for example, predictions of the D and Ds meson decay constants, predictions of the shape of the semileptonic D-meson form factors, and lattice calculations of semileptonic B-meson form factors that yield the most precise determinations of the associated CKM matrix elements, Vcb and Vub to date. Other recent highlights are the most precise calculations of (a) the semileptonic Kaon form factor which improves upon our knowledge of the CKM matrix element Vus, (b) the complete set of semileptonic form factors for B-meson decays to pions, and kaons, yielding new interesting constraints on models of new physics, (c) the complete set of the neutral B and Bs meson mixing matrix elements, yielding the best-to-date constraints on Vtd, Vts, and their ratio, and (d) the first precise calculation of the strong isospin breaking corrections to the hadronic vacuum polarization contribution to the muon 's anomalous magnetic moment.

Teaching Honors

  • Collins Award for Innovative Teaching, COE (2002)
  • Distinguished Scholar, Fermilab (2016)
  • Fellow, American Physical Society (2011)
  • Center for Advanced Study Associate (2007)
  • Frontier Fellow, Fermilab (2002)
  • Beckman Fellow in the Center for Advanced Study (1998)
  • Xerox for Faculty Research Award (1998)
  • A. P. Sloan Foundation Fellow (1997)
  • DOE Outstanding Junior Investigator Award (1996)
  • Studienstiftung des Deutschen Volkes (1988)

Semesters Ranked Excellent Teacher by Students

Fall 2018PHYS 213

Selected Articles in Journals

Articles in Conference Proceedings

Related news

  • In the Media

As early as March, the Muon g-2 experiment at Fermi National Accelerator Laboratory (Fermilab) will report a new measurement of the magnetism of the muon, a heavier, short-lived cousin of the electron. The effort entails measuring a single frequency with exquisite precision. In tantalizing results dating back to 2001, g-2 found that the muon is slightly more magnetic than theory predicts. If confirmed, the excess would signal, for the first time in decades, the existence of novel massive particles that an atom smasher might be able to produce, says Aida El-Khadra, a theorist at the University of Illinois, Urbana-Champaign. “This would be a very clear sign of new physics, so it would be a huge deal.”

  • In the Media

The goal of the experiment, Fermilab Muon g-2, is to better understand the properties of muons, which are essentially heavier versions of electrons, and use them to probe the limitations of the Standard Model of particle physics. Specifically, physicists want to know about the muons’ “magnetic moment”—that is, how much do they rotate on their axes in a powerful magnetic field— as they race around the magnet? 

  • In the Media

For decades, scientists studying the muon have been puzzled by a strange pattern in the way muons rotate in magnetic fields, one that left physicists wondering if it can be explained by the Standard Model — the best tool physicists have to understand the universe.

This week, an international team of more than 170 physicists published the most reliable prediction so far for the theoretical value of the muon’s anomalous magnetic moment, which would account for its particular rotation, or precession. The magnetic moment of subatomic particles is generally expressed in terms of the dimensionless Landé factor, called g. While a number of international groups have worked separately on the calculation, this publication marks the first time the global theoretical physics community has come together to publish a consensus value for the muon’s magnetic moment.