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Indiana University Bloomington

J. Timothy Londergan

J. Timothy Londergan Emeritus Professor
Nuclear Physics (Theoretical)

B.S., University of Rochester, 1965.
Ph.D., Oxford University, 1969.
Postdoctoral Position: Case Western Reserve University, University of Wisconsin

Phone: Swain West 306 (812)855-9687 | NTC (812)855-2956
Email: tlonderg at indiana.edu

NTC Webpage


Quark-Nuclear Physics
My research interest is in theoretical nuclear physics. I study the interface between high energy and nuclear physics. In particular, I am interested in the quark/gluon structure of the nucleon (proton or neutron), and in how the nucleus can be used to obtain information regarding the nucleon's structure. I am particularly interested in the status of "broken symmetries" for quarks. These are symmetries that are approximately, but not exactly, satisfied for quark systems. Such symmetries are particularly interesting because when the symmetries are broken, it gives you direct evidence for "non-perturbative" effects of quarks. Such effects are quite interesting, and are otherwise hard to disentangle from other properties of quarks, nucleons and nuclei.

Nanotechnology; Quantum Wires
In addition, I am interested in "quantum wires", very narrow 2-dimensional structures in which electrons can move freely. Electrons in quantum wires have exactly the same properties as EM fields in rectangular waveguides. This is part of the new field of "nanotechnology". We have known for a long time that all particles possess both wave and particle properties. The dimensions of these structures are roughly the same as the de Broglie wavelength of a cold electron. As a result, electron "wave" properties dominate these devices.

The Electron-Ion Collider
I have also been interested in the possibility of a new facility to study quark-nuclear physics. This machine would collide beams of high-energy electrons (of energy roughly 10 GeV) with beams of protons and light ions, or with beams of "heavy ions" such as gold nuclei. The energies of the protons or heavy ions would be in the range 30 to 200 GeV. There have been several workshops to investigate what such a machine could accomplish, and the properties of such a facility, now called the "Electron-Ion Collider", or EIC.


Selected Publications

  • J.T. Londergan and A.W. Thomas, The Validity of Charge Symmetry for Parton Distributions, Progress in Particle and Nuclear Physics41, 49 (1998).
  • C. Boros, J.T. Londergan and A.W. Thomas, Evidence for Substantial Charge Symmetry Violation in Parton Distributions, Phys. Rev. Letters 81, 4075 (1998).
  • C. Boros, J.T. Londergan and A.W. Thomas, Structure and Production of Lambda Baryons, Phys. Rev. D61, 014007 (2000).
  • S. Kumano and J.T. Londergan, Origin of SU(2) Flavor Symmetry Breaking in Antiquark Distributions, Phys. Rev. D44, 717 (1991).