- In the Media
A result that has been 20 years in the making could reveal the existence of new particles, and upend fundamental physics.
Aida X El-Khadra
Professor
Primary Research Area
- High Energy Physics
Biography
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
| Semester | Course | Outstanding |
|---|---|---|
| Fall 2018 | PHYS 213 |
Selected Articles in Journals
- P. Gambino, A. S. Kronfeld, M. Rotondo, C. Schwanda, F. Bernlochner, A. Bharucha, C. Bozzi, M. Calvi, L. Cao, G. Ciezarek, C. T. H. Davies, A. X. El-Khadra, S. Hashimoto, M. Jung, A. Khodjamirian, Z. Ligeti. Challenges in semileptonic B decays. European Physical Journal C 80:10, 966 (2020) .
- D. Luo, J. Y. Shen, M. Highman, B. K. Clark, B. DeMarco, A. X. El-Khadra, B. Gadway. Framework for simulating gauge theories with dipolar spin systems. Phys. Rev. A 102:3, 32617 (2020)
- C. T. H. Davies et al. [Fermilab Lattice, LATTICE-HPQCD and MILC Collaborations] Hadronic-vacuum-polarization contribution to the muon's anomalous magnetic moment from four-flavor lattice QCD, Phys. Rev. D101, 034512 (2020).
- C. Lehner et al. [USQCD Collaboration], Opportunities for Lattice QCD in Quark and Lepton Flavor Physics, Eur. Phys. J. A55:11, 195 (2019).
- A. Bazavov et al. [Fermilab Lattice and MILC Collaborations]. Bs→Klν decay from lattice QCD. Phys. Rev. D 100, 034501 (2019).
- A. Bazavov, et al. [Fermilab Lattice and MILC Collaborations] |Vus| from Kl3 decay and four-flavor lattice QCD. Phys. Rev. D 99, 114509 (2019).
- A. Bazavov, et al.). [Fermilab Lattice and MILC and TUMQCD Collaborations]. Up-, down-, strange-, charm-, and bottom-quark masses from four-flavor lattice QCD . Phys.Rev. D98, 054517 (2018).
- A. Bazavov, et al. B- and D-meson leptonic decay constants from four-flavor lattice QCD et al.. Dec 26, 2017. Phys.Rev. D98, 074512 (2018).
- B. Chakraborty, et al [Fermilab Lattice, MILC, and HPQCD Collaborations]. Strong-isospin-breaking correction to the muon anomalous magnetic moment from lattice QCD at the physical point. Phys.Rev.Lett. 120, 152001 (2018).
- A. Bazavov, et al [Fermilab Lattice and MILC Collaborations]. Short-distance matrix elements for D0-meson mixing for Nf=2+1 lattice QCD. Phys. Rev. D97, 034513 (2018).
- A. Bazavov, et al [Fermilab Lattice and MILC Collaborations]. B0(s)-mixing matrix elements from lattice QCD for the Standard Model and beyond. Phys. Rev. D 93, 113016 (2016).
- Daping Du, A.X. El-Khadra, Steven Gottlieb, A.S. Kronfeld, J. Laiho, E. Lunghi, R.S. Van de Water, Ran Zhou. Phenomenology of Semileptonic B-Meson Decays with Form Factors from Lattice QCD. Phys. Rev. D 93, 034005 (2016).
- J.A. Bailey et al. B -> Kl+l- decay form factors from three-flavor lattice QCD. Phys. Rev. D 93, 025026 (2016).
- J.A. Bailey, et al. B →πll Form Factors for New-Physics Searches from Lattice QCD.Phys. Rev. Lett. 115, 152002 (2015).
- J.A. Bailey et al. |Vub| from B -> pi decays and (2+1)-flavor lattice QCD. arXiv:1503.07839 [hep-lat]. Phys.Rev. D92 (2015) 1, 014024.
- J. Bailey et al. The B → Dlv form factors at nonzero recoil and |Vcb| from 2+1-flavor lattice QCD. Phys.Rev. D92, 034506 (2015).
- A. Bazavov et al. Charmed and light pseudoscalar meson decay constants from four-flavor lattice QCD with physical light quarks. Phys. Rev. D90, 074509 (2014).
- J. Bailey, et al. Update of |Vcb| from the B → D*lnu-bar form factor at zero recoil with three-flavor lattice QCD. Phys. Rev. D89, 114504 (2014).
- A. Bazavov, et al. Determination of |Vus| from a lattice-QCD calculation of the K -> pi l nu semileptonic form factor with physical quark masses. Phys.Rev.Lett. 112, 112001 (2014).
- S. Aoki, et al. Review of lattice results concerning low energy particle physics. Eur. Phys. J. C74 2890 (2014).
- A. Bazavov, et al. Kaon semileptonic vector form factor and determination of |V_{us}| using staggered fermions. Phys. Rev. D 87, 073012. (2013)
- Jon A. Bailey, et al. Refining new-physics searches in B->D tau nu decay with lattice QCD. Phys. Rev. Lett. 109, 071802 (2012).
- A. Bazavov, et al. Neutral B-meson mixing from three-flavor lattice QCD: Determination of the SU(3)-breaking ratio xi. Phys. Rev. D86 034503 (2012).
- Jon A. Bailey, et al. Bs -> Ds/B->D Semileptonic Form-Factor Ratios and Their Application to BR(B0s -> mu+ mu-). Phys. Rev. D85, 114502 (2012).
- A. Bazavov, et al. B- and D-meson decay constants from three-flavor lattice QCD. Phys. Rev. D85, 114506 (2012).
- C. Bernard, et al. Tuning Fermilab Heavy Quarks in 2+1 Flavor Lattice QCD with Application to Hyperfine Splittings. Phys. Rev. D83, 034503 (2011).
- T. Burch, et al. Quarkonium mass splittings in three-flavor lattice QCD. Phys. Rev. D 81, 034508 (2010).
- C. Bernard et al. Visualization of semileptonic form factors from lattice QCD. Phys. Rev. D 80, 034026 (2009).
- J. Bailey et al. The B -> pi l nu semileptonic form factor from three-flavor lattice QCD: A model-independent determination of |V(ub)|. Phys. Rev. D 79, 054507 (2009).
- C. Bernard, et al. The Anti-B ---> D* l anti-nu form factor at zero recoil from three-flavor lattice QCD: A Model independent determination of |V(cb)|. Phys. Rev. D 79, 014506 (2009).
- 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).
- A. X. El-Khadra, A. S. Kronfeld, P. B. Mackenzie, S. M. Ryan, and J. N. Simone. Semileptonic decays B-> pi l nu and D-> pi l nu from lattice QCD . Phys. Rev. D 64, 014502-1-18 (2001).
- S. Hashimoto, A. X. El-Khadra, A. S. Kronfeld, P. B. Mackenzie, S. M. Ryan, and J. N. Simone. Lattice QCD calculation of B -> D lepton anti-neutrino decay form-factors at zero recoil. Phys. Rev. D 61, 014502 (1999).
- B.P.G. Mertens, A.S. Kronfeld, and A.X. El-Khadra. The self energy of massive lattice fermions. Phys. Rev. D 58, 034505 (1998).
- A.X. El-Khadra, A.S. Kronfeld, P.B. Mackenzie, S.M. Ryan, and J.N. Simone. B and D meson decay constants in lattice QCD. Phys.Rev. D 58, 014506-1-10 (1998).
- B. Gough , et al. The light quark masses from lattice gauge theory. Phys. Rev. Lett. 79, 1622 (1997).
- A. X. El-Khadra, A. Kronfeld, and P. Mackenzie. Massive quarks in lattice QCD. Phys. Rev. D 3933-3957 (1997).
Articles in Conference Proceedings
- Jiayu Shen, Di Luo, Michael Highman, Bryan K. Clark, Brian DeMarco, Bryce Gadway, "(1+1)-d U(1) Quantum link models from effective Hamiltonians of dipolar molecules," PoS LATTICE2019 (2020) 125; arXiv:2001.10002 [hep-lat].
- Z. Gelzer, C. DeTar, A.X. El-Khadra, E. Gámiz, Steven Gottlieb, Andreas S. Kronfeld, Yuzhi Liu, Y. Meurice, J.N. Simone, D. Toussaint, R.S. Van de Water [Fermilab Lattice and MILC Collaborations], "B-Meson Semileptonic Form Factors on (2+1+1)-Flavor HISQ Ensembles," proceedings of the 37th International Symposium on Lattice Field Theory (Lattice 2019), 16-22 June 2019. Wuhan, Hubei, China, arXiv:1912.13358 [hep-lat]
- [Fermilab Lattice and MILC Collaborations], "The $B \to D^* \ell \nu$ Semileptonic Decay at Nonzero Recoil and Its Implications for $|V_{cb}|$ and $R(D^*)," proceedings of the 37th International Symposium on Lattice Field Theory (Lattice 2019), 16-22 June 2019. Wuhan, Hubei, China, arXiv:1912.05886 [hep-lat].
- C.E. DeTar et al [Fermilab Lattice, HPQCD, and MILC Collaborations], "The Hadronic Vacuum Polarization of the Muon from Four-Flavor Lattice QCD," proceedings of the 37th International Symposium on Lattice Field Theory (Lattice 2019), 16-22 June 2019. Wuhan, Hubei, China, arXiv:1912.04382 [hep-lat].
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.